Learn by Novus · Open practice pack v1

Logical reasoning: full practice bank: open practice pack

100 untimed questions across 10 authored sections.

This is untimed educational practice for one cognitive skill. It is not a clinical, diagnostic, employment, or professionally recognized assessment, and it does not produce an IQ score or credential.

Learner worksheet

One hundred deduction problems in ten themed sections, starting with single rules and building up to chains of them. Everything you need is in each prompt. Treat the statements as given and work out only what must follow from them. Take as long as you like; noticing the step where a conclusion overreaches matters far more than answering quickly.

Choose one answer for each item. For a delayed-recall item, read its study text, cover it, and then answer without looking back.

Reading conditional statements

Each item gives an if–then rule plus one extra fact. Decide what must follow from the rule as written, and nothing more.

1. logical-reasoning-s01-q01

If the fire alarm sounds, the building is evacuated. This morning the fire alarm sounded. What must be true?

  1. The building was evacuated.
  2. The building was not evacuated.
  3. The alarm was faulty.
  4. Nothing can be established about the evacuation.

Answer:

2. logical-reasoning-s01-q02

A courier firm's rule: if a parcel weighs more than 2 kg, it must carry a green label. A parcel on the belt weighs 3.4 kg. What follows?

  1. The parcel carries no label.
  2. The parcel must carry a green label.
  3. Only parcels over 2 kg carry green labels.
  4. The parcel is too heavy to post.

Answer:

3. logical-reasoning-s01-q03

'If the road is icy, the morning bus is delayed.' Which statement is guaranteed by this rule on its own?

  1. The road is icy whenever the bus is delayed.
  2. Ice is the only thing that delays the bus.
  3. Every time the road is icy, the bus is delayed.
  4. The bus is never delayed when the road is clear.

Answer:

4. logical-reasoning-s01-q04

If Ravi finishes the audit today, he will leave early. Ravi did not finish the audit today. What follows?

  1. He will not leave early.
  2. He will leave early.
  3. He never leaves early.
  4. Whether he leaves early is undetermined.

Answer:

5. logical-reasoning-q5

If a shipment passes quality control, it is approved for delivery. This shipment was not approved for delivery. What follows?

  1. The shipment passed quality control.
  2. The shipment did not pass quality control.
  3. The shipment was delivered anyway.
  4. Quality control was skipped.

Answer:

6. logical-reasoning-s01-q06

If a member's subscription lapses, their gym card stops working. Nadia's gym card still works. What must be true?

  1. Her subscription has not lapsed.
  2. Her subscription has lapsed.
  3. She renewed her subscription this month.
  4. Nothing can be established.

Answer:

7. logical-reasoning-s01-q07

A council rule states: if a skip is left on the road overnight, it must display a warning lamp. A skip on Mill Lane displays no warning lamp, and the council rule has not been broken. What follows?

  1. The skip was left on the road overnight.
  2. The skip needs no permit.
  3. Warning lamps are used only on skips.
  4. The skip was not left on the road overnight.

Answer:

8. logical-reasoning-s01-q08

If the printer is out of toner, the status light turns amber. The status light is amber. Which is the safe conclusion?

  1. The printer is out of toner.
  2. The printer has plenty of toner.
  3. The amber light may have another cause, so the toner level is undetermined.
  4. The status light is faulty.

Answer:

9. logical-reasoning-s01-q09

If a seminar is oversubscribed, a second session is added. A second session has been added, and at this college no other reason for adding a session exists. What follows?

  1. The seminar was undersubscribed.
  2. The seminar was oversubscribed.
  3. The second session will also fill.
  4. Nothing follows.

Answer:

10. logical-reasoning-s01-q10

If a train is cancelled, its passengers may claim a refund. Passengers on the 08:12 may claim a refund. What can be concluded about the 08:12?

  1. It ran on time.
  2. It was cancelled.
  3. It was delayed rather than cancelled.
  4. Its status cannot be settled from the rule alone.

Answer:

Categorical statements: all, no, and some

These items use 'all', 'no', and 'some'. Track which group sits inside which, and take care with statements that describe only part of a group.

11. logical-reasoning-q1

All engineers at Northfield Robotics hold a safety-protocols certification. Priya works at Northfield Robotics. Which conclusion follows with certainty?

  1. Priya is an engineer.
  2. Priya holds a safety-protocols certification.
  3. If Priya holds the certification, she is an engineer.
  4. It cannot be determined whether Priya holds the certification.

Answer:

12. logical-reasoning-s02-q02

All harbour tours depart from Quay 3. The 10:00 sailing is a harbour tour. Where does it depart from?

  1. Quay 1
  2. Quay 3
  3. Quay 3, but only if the tide allows
  4. It cannot be determined.

Answer:

13. logical-reasoning-s02-q03

No item in the archive room may be borrowed. The 1904 ledger is kept in the archive room. What follows?

  1. The 1904 ledger may not be borrowed.
  2. The 1904 ledger may be borrowed with permission.
  3. Some archive items may be borrowed.
  4. The ledger is the only item that may not be borrowed.

Answer:

14. logical-reasoning-s02-q04

Some of the pupils in Year 9 study Latin. Which of these is guaranteed?

  1. Most Year 9 pupils study Latin.
  2. Fewer than half of Year 9 study Latin.
  3. At least one Year 9 pupil studies Latin.
  4. Not all Year 9 pupils study Latin.

Answer:

15. logical-reasoning-q4

No amphibians are reptiles. All salamanders are amphibians. Which conclusion is valid?

  1. No salamanders are reptiles.
  2. Some salamanders are reptiles.
  3. All reptiles are salamanders.
  4. No conclusion can be drawn.

Answer:

16. logical-reasoning-s02-q06

All the flats in Rowan Court have a balcony. Some of the flats in Rowan Court are rented out. What must be true?

  1. Only the rented flats have balconies.
  2. Some flats in the block have no balcony.
  3. All the rented flats in the block have a balcony.
  4. Most flats in the block are rented out.

Answer:

17. logical-reasoning-s02-q07

No delivery driver at the depot works on Sundays. Petra works at the depot on Sundays. What follows?

  1. Petra is a delivery driver.
  2. Petra is not a delivery driver.
  3. The depot is closed on Sundays.
  4. Nothing follows.

Answer:

18. logical-reasoning-s02-q08

All the delegates staying at the Riverside Hotel travel by coach. Nobody travelling by coach arrives before nine. Which must be true?

  1. Everyone arriving after nine travels by coach.
  2. Some Riverside delegates arrive before nine.
  3. Only Riverside delegates travel by coach.
  4. No delegate staying at the Riverside Hotel arrives before nine.

Answer:

19. logical-reasoning-s02-q09

All the paramedics at the station have completed the advanced driving course. All the fire crew at the station have completed the advanced driving course. Which must be true?

  1. Every paramedic is also on the fire crew.
  2. No paramedic is on the fire crew.
  3. Both groups have completed that course.
  4. Only station staff may take the course.

Answer:

20. logical-reasoning-s02-q10

Every machine carrying a green tag has been serviced. Some machines in the workshop have not been serviced. What follows?

  1. No machine in the workshop carries a green tag.
  2. At least one machine in the workshop carries no green tag.
  3. Every serviced machine carries a green tag.
  4. All the workshop machines will be serviced eventually.

Answer:

Necessary and sufficient conditions

'Only if', 'unless', and 'requires' behave differently from a plain 'if'. For each item, work out whether the condition is enough on its own, needed but not enough, or both.

21. logical-reasoning-s03-q01

To sit the exam, a candidate must have paid the fee. Kofi has paid the fee. What follows?

  1. Kofi will sit the exam.
  2. Kofi may or may not sit the exam.
  3. Kofi cannot sit the exam.
  4. Only Kofi may sit the exam.

Answer:

22. logical-reasoning-s03-q02

Entry to the members' lounge requires a valid pass. Dara does not have a valid pass. What follows?

  1. Dara may not enter the lounge.
  2. Dara may enter with a companion.
  3. Everyone with a pass enters the lounge.
  4. Nothing can be concluded.

Answer:

23. logical-reasoning-s03-q03

'You may borrow the van only if you hold a clean licence.' Rosa holds a clean licence. What follows?

  1. Rosa may borrow the van.
  2. Rosa may not borrow the van.
  3. Anyone borrowing the van has an unclean licence.
  4. Holding the licence does not by itself grant permission.

Answer:

24. logical-reasoning-s03-q04

'The heating switches on if, and only if, the temperature falls below 18°C.' The heating is on. What follows?

  1. The temperature is above 18°C.
  2. The temperature is exactly 18°C.
  3. The temperature is below 18°C.
  4. Nothing can be determined.

Answer:

25. logical-reasoning-s03-q05

Unless the permit is renewed, the market stall must close. The stall has not closed. What follows?

  1. The permit was not renewed.
  2. The stall will close soon.
  3. Nothing follows.
  4. The permit was renewed.

Answer:

26. logical-reasoning-s03-q06

A degree is necessary but not sufficient for the graduate scheme. Ellis has a degree and has applied. What follows?

  1. Ellis will be accepted.
  2. Ellis will be rejected.
  3. Ellis has met one requirement, but acceptance is undetermined.
  4. Only degree holders apply to the scheme.

Answer:

27. logical-reasoning-s03-q07

A ticket is sufficient for entry to the fair. Mira has a ticket. What follows?

  1. Mira may enter the fair.
  2. Mira needs a wristband as well.
  3. Only ticket holders may enter.
  4. Nothing follows.

Answer:

28. logical-reasoning-s03-q08

Passing the practical is sufficient for the certificate, and passing the theory paper is necessary for it. Tomás failed the theory paper. What follows?

  1. He passed the practical.
  2. He received the certificate.
  3. He may still receive the certificate.
  4. He did not receive the certificate.

Answer:

29. logical-reasoning-s03-q09

'Access is granted only to staff who have signed the confidentiality form.' Yusuf has been granted access. What follows?

  1. Yusuf has signed the confidentiality form.
  2. Every member of staff who signed has been granted access.
  3. Yusuf is a manager.
  4. Nothing follows.

Answer:

30. logical-reasoning-s03-q10

Rain is neither necessary nor sufficient for a match to be postponed. Today it rained. What follows about today's match?

  1. It was postponed.
  2. The rain settles nothing about a postponement.
  3. It went ahead.
  4. It will be postponed next time instead.

Answer:

Converse, inverse, and contrapositive

Turning a rule around changes what it claims: sometimes harmlessly, sometimes fatally. These items ask which rearrangements keep the original meaning.

31. logical-reasoning-s04-q01

'If a book is overdue, a reminder is sent.' Which statement carries exactly the same meaning?

  1. If no reminder is sent, the book is not overdue.
  2. If a reminder is sent, the book is overdue.
  3. If a book is not overdue, no reminder is sent.
  4. Reminders are sent only for overdue books.

Answer:

32. logical-reasoning-s04-q02

'If the ferry is cancelled, the harbour flag is lowered.' Which of these is the converse of that rule?

  1. If the flag is not lowered, the ferry is not cancelled.
  2. If the ferry is not cancelled, the flag is not lowered.
  3. The flag is lowered only when the ferry is cancelled.
  4. If the harbour flag is lowered, the ferry is cancelled.

Answer:

33. logical-reasoning-q2

If it rains, the outdoor market is closed. The outdoor market is closed today. Which of the following must be true?

  1. It rained today.
  2. It did not rain today.
  3. It is not necessarily true that it rained today.
  4. The market is always closed when it doesn't rain.

Answer:

34. logical-reasoning-s04-q04

'If a student is on the exchange programme, they have a language tutor.' Rafi is not on the exchange programme. Which conclusion is unsafe?

  1. Rafi may still have a language tutor.
  2. Rafi therefore has no language tutor.
  3. The rule says nothing about students outside the programme.
  4. Tutors may be assigned for other reasons.

Answer:

35. logical-reasoning-s04-q05

'Only ticket holders may enter the paddock.' Which statement says the same thing?

  1. If someone enters the paddock, they hold a ticket.
  2. If someone holds a ticket, they enter the paddock.
  3. Ticket holders must enter the paddock.
  4. Everyone outside the paddock lacks a ticket.

Answer:

36. logical-reasoning-q3

Every certified diver on the boat is wearing a wetsuit. Tomas is wearing a wetsuit. Which conclusion is valid?

  1. Tomas is a certified diver.
  2. Tomas may or may not be a certified diver.
  3. Everyone wearing a wetsuit is a certified diver.
  4. Tomas is not on the boat.

Answer:

37. logical-reasoning-s04-q07

'No unregistered vehicle may use the site.' A van is using the site, and the rule has been observed. Which conclusion follows?

  1. The van is the only registered vehicle.
  2. Every registered vehicle uses the site.
  3. The van may be unregistered.
  4. The van is registered.

Answer:

38. logical-reasoning-s04-q08

'If the alarm is armed, the porch light flashes twice.' The porch light did not flash twice. Which conclusion follows, and what is that pattern called?

  1. The alarm is armed: modus ponens.
  2. The alarm may be armed: affirming the consequent.
  3. The alarm is not armed: modus tollens.
  4. Nothing follows: denying the antecedent.

Answer:

39. logical-reasoning-s04-q09

'Whenever the tide is out, the causeway is passable.' The causeway is passable this afternoon. Which is the safest conclusion?

  1. The tide is out.
  2. The tide is in.
  3. The state of the tide is undetermined.
  4. The causeway is never passable at high tide.

Answer:

40. logical-reasoning-s04-q10

'If a claim form is incomplete, it is returned to the sender.' One claim form was not returned to the sender, and the rule was applied correctly. Which pair of conclusions is right?

  1. The form was incomplete, and it was processed anyway.
  2. The form was complete, and the rule was respected.
  3. The form was incomplete, and the rule was broken.
  4. Nothing at all follows.

Answer:

Or, and, and not: combining statements

These items join statements with 'either … or', 'both … and', and negation. Read 'or' as inclusive (at least one, possibly both) unless an item says otherwise.

41. logical-reasoning-s05-q01

The report is both signed and dated. Which statement must be false?

  1. The report is signed.
  2. The report is dated.
  3. The report is undated.
  4. The report was signed by a manager.

Answer:

42. logical-reasoning-q6

Either the meeting is rescheduled, or Priya will miss her flight. Priya did not miss her flight. What follows?

  1. The meeting was rescheduled.
  2. The meeting was not rescheduled.
  3. Priya missed her flight.
  4. Nothing can be determined.

Answer:

43. logical-reasoning-s05-q03

It is not the case that the shop is both open and staffed. The shop is open. What follows?

  1. The shop is closed.
  2. The shop is not staffed.
  3. The shop is staffed.
  4. Nothing follows.

Answer:

44. logical-reasoning-s05-q04

'Neither the projector nor the microphone was working.' Which statement must be true?

  1. The projector worked but the microphone did not.
  2. At least one of the two was working.
  3. The room had no power.
  4. The projector was not working.

Answer:

45. logical-reasoning-s05-q05

The office opens on Saturday or on Sunday, but never on both days. This weekend it opened on Sunday. What follows?

  1. It was closed on Saturday.
  2. It was open on Saturday.
  3. It opens every weekend.
  4. Nothing follows.

Answer:

46. logical-reasoning-s05-q06

Either the parcel was mislabelled or it was sent to the wrong depot, and possibly both. The parcel was sent to the wrong depot. What follows about the label?

  1. It was mislabelled.
  2. It was labelled correctly.
  3. Its labelling is undetermined.
  4. Both faults occurred.

Answer:

47. logical-reasoning-s05-q07

'It is not true that the bid was late or incomplete.' Which must be true?

  1. The bid was late but complete.
  2. The bid was neither late nor incomplete.
  3. The bid was incomplete but on time.
  4. The bid was rejected.

Answer:

48. logical-reasoning-s05-q08

The alarm sounds if the door is forced or the window is broken. The alarm has not sounded, and it is in working order. What follows?

  1. The door was forced.
  2. The window was broken.
  3. Only the window is intact.
  4. Neither was the door forced nor the window broken.

Answer:

49. logical-reasoning-s05-q09

Exactly one of these three statements about an invoice is true: it was paid; it was cancelled; it is still outstanding. The invoice was not cancelled and is not outstanding. What follows?

  1. It was cancelled after all.
  2. Nothing can be settled.
  3. It was paid.
  4. Two of the statements are true.

Answer:

50. logical-reasoning-s05-q10

A grant is awarded to anyone who is both a resident and under twenty-five. Devi is under twenty-five and was not awarded a grant. What follows?

  1. Devi is not a resident.
  2. Devi is a resident.
  3. The scheme has closed.
  4. Devi applied too late.

Answer:

Ordering and ranking

Each item describes positions in a line, a stack, or a ranking. Sketching the order on paper often settles an item in seconds; assume no ties unless stated.

51. logical-reasoning-s06-q01

Five runners finish a race with no ties. Amara finishes ahead of Ben, and Ben finishes ahead of Chen. Who is known to have finished ahead of Chen?

  1. Ben only
  2. Both Amara and Ben
  3. Amara only
  4. It cannot be determined.

Answer:

52. logical-reasoning-s06-q02

Four books are stacked. The novel is on top and the thesaurus is at the bottom. The atlas is directly above the dictionary. Which book is second from the bottom?

  1. The novel
  2. The atlas
  3. The dictionary
  4. The thesaurus

Answer:

53. logical-reasoning-s06-q03

In a queue of six people, Rita is third from the front and Sam stands directly behind her. How many people are in front of Sam?

  1. Three
  2. Two
  3. Four
  4. Five

Answer:

54. logical-reasoning-s06-q04

Three towns lie along a straight road. Ashby is west of Barrow, and Carn is east of Barrow. Which town lies between the other two?

  1. Ashby
  2. Carn
  3. It cannot be determined.
  4. Barrow

Answer:

55. logical-reasoning-s06-q05

Five candidates are ranked first to fifth with no ties. Priya ranks higher than Omar, Omar ranks higher than Nia, and Nia ranks fourth. Which must be true?

  1. Priya ranks first.
  2. Omar ranks first.
  3. Nia ranks above Omar.
  4. Priya ranks either first or second.

Answer:

56. logical-reasoning-s06-q06

Six carriages are lettered A to F and counted from the front of the train. Carriage D is immediately behind C, and C is immediately behind B. If B is third from the front, which carriage is fifth?

  1. D
  2. C
  3. E
  4. F

Answer:

57. logical-reasoning-s06-q07

Four athletes are ranked by score with no ties. Jonas scored more than Kemi, Lars scored less than Kemi, and Mira scored more than Jonas. Who came third?

  1. Jonas
  2. Lars
  3. Kemi
  4. Mira

Answer:

58. logical-reasoning-s06-q08

Five parcels are stacked one above another. The heaviest is neither at the top nor at the bottom. What can be said about its position?

  1. It is exactly in the middle.
  2. It is second from the top.
  3. It is fourth from the top.
  4. It lies somewhere between second and fourth from the top.

Answer:

59. logical-reasoning-s06-q09

Three tasks must be done in order: the survey before the report, and the report before the presentation. The presentation is on Friday and the report on Wednesday. On which day could the survey not be done?

  1. Monday
  2. Thursday
  3. Tuesday
  4. Sunday

Answer:

60. logical-reasoning-s06-q10

Seven flats are numbered 1 to 7 from the ground floor upwards, one per floor. Ravi lives on the middle floor, and Nadia lives two floors above him. Which flat is Nadia's?

  1. Flat 6
  2. Flat 5
  3. Flat 7
  4. Flat 4

Answer:

Grouping and matching constraints

Each item gives a small set of constraints about who or what goes where. Place the fixed clues first, then use elimination to close the gaps.

61. logical-reasoning-s07-q01

Three colleagues (Ines, Jed, and Kwame) each take exactly one of three roles: chair, timekeeper, or notetaker. Ines is not the chair. Jed is the notetaker. Which role does Ines take?

  1. Chair
  2. Notetaker
  3. It cannot be determined.
  4. Timekeeper

Answer:

62. logical-reasoning-s07-q02

Four pupils each chose a different instrument: violin, cello, flute, or drums. Ana chose a string instrument. Ben chose neither the flute nor a string instrument. Which instrument did Ben choose?

  1. Flute
  2. Drums
  3. Violin
  4. Cello

Answer:

63. logical-reasoning-s07-q03

Three parcels of different weights go to three different cities: Leeds, Derby, and Hull. The heaviest parcel does not go to Hull, and the parcel for Derby is the lightest. Where does the heaviest parcel go?

  1. Hull
  2. Derby
  3. Leeds
  4. It cannot be determined.

Answer:

64. logical-reasoning-s07-q04

Four friends sit at a square table, one to a side, all facing the centre. Priya sits opposite Quinn, and Rohan sits on Priya's left. Where does Sana sit?

  1. On Priya's right
  2. Opposite Priya
  3. On Rohan's left
  4. It cannot be determined.

Answer:

65. logical-reasoning-s07-q05

Three boxes hold red, green, and blue counters, one colour per box. Box 1 does not hold the red counters. Box 2 holds neither the red nor the green counters. Which box holds the red counters?

  1. Box 1
  2. Box 3
  3. Box 2
  4. It cannot be determined.

Answer:

66. logical-reasoning-s07-q06

Four departments (Admin, Billing, Care, and Data) occupy floors 1 to 4, one department per floor. Billing is directly above Admin. Care is on floor 4. Data is not on floor 1. Which floor is Admin on?

  1. Floor 2
  2. Floor 3
  3. Floor 4
  4. Floor 1

Answer:

67. logical-reasoning-s07-q07

Ola, Pia, and Rae each ordered one drink: a tea, a coffee, and a juice, all different. Ola did not order coffee. Pia ordered the juice. Who ordered the coffee?

  1. Rae
  2. Ola
  3. Pia
  4. It cannot be determined.

Answer:

68. logical-reasoning-s07-q08

Five colleagues each work one late shift a week, Monday to Friday, one person per day. Tam works the day after Uma. Uma works neither Monday nor Friday. Vik works Monday. Which days could Tam work?

  1. Tuesday, Wednesday, or Thursday
  2. Wednesday or Thursday only
  3. Wednesday, Thursday, or Friday
  4. Friday only

Answer:

69. logical-reasoning-s07-q09

A three-storey building has one flat per floor, let to a nurse, a pilot, and a teacher. The nurse's flat is not on the top floor, and the pilot lives above the teacher. Who lives on the top floor?

  1. The nurse
  2. The teacher
  3. The pilot
  4. It cannot be determined.

Answer:

70. logical-reasoning-s07-q10

Four items (a lamp, a mirror, a print, and a shelf) sit along one wall in positions 1 to 4 from the left. The print is in position 1 and the shelf in position 4. The mirror is somewhere to the right of the lamp. Which position holds the mirror?

  1. Position 3
  2. Position 2
  3. Position 4
  4. It cannot be determined.

Answer:

Assumptions and hidden premises

Each item gives a short argument. Look for the missing link it needs, the rival explanation it ignores, or the information that would test it.

71. logical-reasoning-s08-q01

'The new filter must be working: complaints about the water's taste have stopped.' Which assumption does this argument depend on?

  1. The filter was expensive.
  2. Complaints used to arrive daily.
  3. Complaints would still be arriving if the filter were not working.
  4. Everyone in the building drinks the tap water.

Answer:

72. logical-reasoning-s08-q02

'Our library should extend its opening hours, because more students would then use it.' Which assumption is required?

  1. Increasing student use is a goal worth pursuing.
  2. Students currently dislike the library.
  3. The library is short of shelf space.
  4. Other libraries have extended their hours.

Answer:

73. logical-reasoning-s08-q03

'Sunil must be a strong swimmer: he completed the coastal crossing.' What is being assumed?

  1. Sunil trains every day.
  2. The crossing is a popular event.
  3. Sunil has swum since childhood.
  4. Completing the crossing calls for strong swimming.

Answer:

74. logical-reasoning-s08-q04

'The bakery will do well on the high street, because its bread sold out at the farmers' market.' Which assumption does the argument rest on?

  1. The high street has no other bakery.
  2. High-street demand will resemble demand at the market.
  3. The bakery will raise its prices.
  4. Farmers' markets are held weekly.

Answer:

75. logical-reasoning-s08-q05

'Ella will pass her driving test, because she has had thirty lessons.' Which unstated premise would make the argument work?

  1. Ella enjoys driving.
  2. Thirty lessons cost a great deal.
  3. Thirty lessons are enough preparation to pass.
  4. Most learners take fewer lessons than that.

Answer:

76. logical-reasoning-s08-q06

'Fewer accidents were recorded at the junction after the new signs went up, so the signs made the junction safer.' Which possibility, if true, most weakens this?

  1. The signs were inexpensive to install.
  2. Traffic through the junction fell sharply over the same period.
  3. Drivers say the new signs are clear.
  4. Similar signs are used in other towns.

Answer:

77. logical-reasoning-s08-q07

'Everyone who auditioned for the choir was accepted, so the audition cannot be demanding.' What does this overlook?

  1. Only well-prepared singers may have chosen to audition.
  2. The choir rehearses weekly.
  3. Auditions are held once a year.
  4. Some members joined without auditioning.

Answer:

78. logical-reasoning-s08-q08

'The medicine works: nine out of ten patients recovered within a fortnight.' Which question would best test the argument?

  1. How much did the course of treatment cost?
  2. How many patients took part in total?
  3. Was the medicine pleasant to take?
  4. How many untreated patients recover within a fortnight?

Answer:

79. logical-reasoning-s08-q09

'Most people who currently use the app say they are satisfied with it, so most people who have ever tried it are satisfied.' Which assumption does the conclusion require?

  1. The app has a large number of users.
  2. The survey responses were anonymous.
  3. Satisfaction can be measured on a scale.
  4. Those who tried the app and gave it up are not markedly less satisfied.

Answer:

80. logical-reasoning-s08-q10

'Nobody has proved that the old bridge is unsafe, so it must be safe.' What is wrong with this reasoning?

  1. It contradicts itself.
  2. It treats the absence of proof as proof of the opposite.
  3. It generalises from a single case.
  4. It confuses a necessary condition with a sufficient one.

Answer:

Spotting flaws in arguments

Each item presents an argument that goes wrong somewhere. Find the step where the conclusion outruns what the reasons actually support.

81. logical-reasoning-s09-q01

'Either we cancel the whole festival, or we accept that the noise complaints will continue.' Which flaw does this display?

  1. Circular reasoning
  2. Presenting only two options when others exist
  3. Attacking the person rather than the argument
  4. Appealing to popularity

Answer:

82. logical-reasoning-s09-q02

'This policy must be sound, because it was proposed by the longest-serving member of the committee.' Which flaw is this?

  1. Confusing correlation with causation
  2. Generalising from too few cases
  3. Shifting the burden of proof
  4. Treating the source's standing as evidence for the claim

Answer:

83. logical-reasoning-s09-q03

'The proposal is fair, because it treats everybody fairly.' What is the problem?

  1. The conclusion is simply restated as the reason for it.
  2. The evidence offered is out of date.
  3. The sample is unrepresentative.
  4. The terms used contradict each other.

Answer:

84. logical-reasoning-s09-q04

'Two of my neighbours found the new timetable confusing, so the timetable confuses the whole town.' Which flaw is this?

  1. A false dilemma
  2. An appeal to tradition
  3. A hasty generalisation from a very small sample
  4. Circular reasoning

Answer:

85. logical-reasoning-s09-q05

'My opponent wants to trim the road-repair budget, so plainly they do not care whether anyone gets home safely.' Which flaw is this?

  1. An appeal to popularity
  2. Misrepresenting a position to make it easier to attack
  3. Confusing necessary and sufficient conditions
  4. Circular reasoning

Answer:

86. logical-reasoning-s09-q06

'Ninety per cent of the readers surveyed prefer the new layout, so the new layout is better.' Which step needs more support?

  1. That ninety per cent is a large share
  2. That readers were surveyed at all
  3. That whatever most people prefer is thereby better
  4. That two layouts can be compared

Answer:

87. logical-reasoning-s09-q07

'If we let one stall open early, before long the whole market will be trading through the night.' Which flaw is this?

  1. Circular reasoning
  2. An appeal to authority
  3. A hasty generalisation
  4. A slippery-slope claim with no support for the chain of steps

Answer:

88. logical-reasoning-s09-q08

'The society's rules are very old, and old rules are the ones that have stood the test of time, so these rules should not be changed.' Where is the weak point?

  1. Age is treated as evidence of merit.
  2. The rules themselves are never quoted.
  3. The society is a small one.
  4. The argument offers a false dilemma.

Answer:

89. logical-reasoning-s09-q09

'Ice-cream sales and cases of sunburn both rose sharply in June, so buying ice cream causes sunburn.' Which flaw is this?

  1. A false dilemma
  2. An attack on the person making the claim
  3. Mistaking a shared cause for a direct one
  4. Circular reasoning

Answer:

90. logical-reasoning-s09-q10

'Every part of this bicycle is light, so the bicycle is light.' Why is this unsafe?

  1. A property of each part need not carry over to the whole.
  2. The parts may be of different colours.
  3. Bicycles are not usually weighed.
  4. The argument offers a false dilemma.

Answer:

Combining rules: multi-step deduction

This final section chains several rules together. Take one rule at a time, note what each new fact forces, and stop as soon as the question is answered. Some details are there only to be set aside.

91. logical-reasoning-s10-q01

If the shipment clears customs, it reaches the depot by Friday. If it reaches the depot by Friday, the shop is restocked at the weekend. The shop was not restocked at the weekend. What follows?

  1. The shipment did not clear customs.
  2. The shipment cleared customs.
  3. The shipment reached the depot by Friday.
  4. Nothing follows.

Answer:

92. logical-reasoning-s10-q02

All members of the walking group hold a valid first-aid card. Anyone holding a valid first-aid card has attended a training day within the past two years. Dev has not attended a training day within the past two years. What follows?

  1. Dev holds a first-aid card.
  2. Dev is a member of the walking group.
  3. Dev is not a member of the walking group.
  4. Dev's membership cannot be settled.

Answer:

93. logical-reasoning-s10-q03

If the server is patched, the audit passes. If the audit passes, the release goes ahead. The release went ahead. What follows about the server?

  1. It was patched.
  2. Its state cannot be settled from these rules.
  3. It was not patched.
  4. The audit failed.

Answer:

94. logical-reasoning-s10-q04

Three rules govern a workshop: only trained staff may use the press; anyone using the press must sign the log; today the log was signed by Marta alone. Assuming the rules were followed and the press was used today, which conclusion is safe?

  1. Marta is the only trained member of staff.
  2. Nobody used the press today.
  3. Marta signed the log but did not use the press.
  4. Marta used the press and is trained.

Answer:

95. logical-reasoning-s10-q05

Whenever the reservoir is below half full, the sprinklers are switched off. Whenever the sprinklers are off, the lawn signs are displayed. The lawn signs are not displayed. What follows?

  1. The reservoir is below half full.
  2. The sprinklers are switched off.
  3. Nothing follows.
  4. The reservoir is at least half full.

Answer:

96. logical-reasoning-s10-q06

Four facts about a fixture: if the pitch is frozen the match is postponed; if the match is postponed the club refunds tickets; the club did not refund tickets; the pitch inspection took place at noon. Which conclusion follows?

  1. The pitch was not frozen.
  2. The pitch was frozen.
  3. The match was postponed.
  4. The inspection was cancelled.

Answer:

97. logical-reasoning-s10-q07

Every book in the reference section is catalogued. No catalogued book leaves the building. A book left the building today. What follows?

  1. The book was catalogued.
  2. The book did not come from the reference section.
  3. The reference section is closed.
  4. The book will be returned.

Answer:

98. logical-reasoning-s10-q08

Three grant rules, all followed: applicants must be registered; registered applicants must submit two references; anyone submitting two references receives an acknowledgement. Iris received no acknowledgement. Which conclusion is safest?

  1. Iris submitted two references.
  2. Iris is registered but was overlooked.
  3. Iris will receive her grant late.
  4. Iris is not registered.

Answer:

99. logical-reasoning-s10-q09

A site has exactly two gates. Either the north gate or the south gate is unlocked, and possibly both. If the north gate is unlocked, the security light is on. The security light is off and working normally. What follows?

  1. The north gate is unlocked.
  2. The south gate is unlocked.
  3. Both gates are locked.
  4. Nothing follows.

Answer:

100. logical-reasoning-s10-q10

Facts about a delivery: it is either early or late, never both; if it is early the driver waits; if the driver waits the office is notified; the office was not notified; the depot closes at six. What follows?

  1. The delivery is early.
  2. The driver waited.
  3. The delivery is late.
  4. Nothing follows.

Answer:

Authored hints

This cognitive practice source does not publish authored hints. Every item is listed as missing a hint, and no hint text is generated or inferred.

100 worksheet items do not have an authored hint.

This source contains no authored hints. No hint text was generated.

Answer key

ItemChoiceAnswer
logical-reasoning-s01-q01AThe building was evacuated.
logical-reasoning-s01-q02BThe parcel must carry a green label.
logical-reasoning-s01-q03CEvery time the road is icy, the bus is delayed.
logical-reasoning-s01-q04DWhether he leaves early is undetermined.
logical-reasoning-q5BThe shipment did not pass quality control.
logical-reasoning-s01-q06AHer subscription has not lapsed.
logical-reasoning-s01-q07DThe skip was not left on the road overnight.
logical-reasoning-s01-q08CThe amber light may have another cause, so the toner level is undetermined.
logical-reasoning-s01-q09BThe seminar was oversubscribed.
logical-reasoning-s01-q10DIts status cannot be settled from the rule alone.
logical-reasoning-q1DIt cannot be determined whether Priya holds the certification.
logical-reasoning-s02-q02BQuay 3
logical-reasoning-s02-q03AThe 1904 ledger may not be borrowed.
logical-reasoning-s02-q04CAt least one Year 9 pupil studies Latin.
logical-reasoning-q4ANo salamanders are reptiles.
logical-reasoning-s02-q06CAll the rented flats in the block have a balcony.
logical-reasoning-s02-q07BPetra is not a delivery driver.
logical-reasoning-s02-q08DNo delegate staying at the Riverside Hotel arrives before nine.
logical-reasoning-s02-q09CBoth groups have completed that course.
logical-reasoning-s02-q10BAt least one machine in the workshop carries no green tag.
logical-reasoning-s03-q01BKofi may or may not sit the exam.
logical-reasoning-s03-q02ADara may not enter the lounge.
logical-reasoning-s03-q03DHolding the licence does not by itself grant permission.
logical-reasoning-s03-q04CThe temperature is below 18°C.
logical-reasoning-s03-q05DThe permit was renewed.
logical-reasoning-s03-q06CEllis has met one requirement, but acceptance is undetermined.
logical-reasoning-s03-q07AMira may enter the fair.
logical-reasoning-s03-q08DHe did not receive the certificate.
logical-reasoning-s03-q09AYusuf has signed the confidentiality form.
logical-reasoning-s03-q10BThe rain settles nothing about a postponement.
logical-reasoning-s04-q01AIf no reminder is sent, the book is not overdue.
logical-reasoning-s04-q02DIf the harbour flag is lowered, the ferry is cancelled.
logical-reasoning-q2CIt is not necessarily true that it rained today.
logical-reasoning-s04-q04BRafi therefore has no language tutor.
logical-reasoning-s04-q05AIf someone enters the paddock, they hold a ticket.
logical-reasoning-q3BTomas may or may not be a certified diver.
logical-reasoning-s04-q07DThe van is registered.
logical-reasoning-s04-q08CThe alarm is not armed: modus tollens.
logical-reasoning-s04-q09CThe state of the tide is undetermined.
logical-reasoning-s04-q10BThe form was complete, and the rule was respected.
logical-reasoning-s05-q01CThe report is undated.
logical-reasoning-q6AThe meeting was rescheduled.
logical-reasoning-s05-q03BThe shop is not staffed.
logical-reasoning-s05-q04DThe projector was not working.
logical-reasoning-s05-q05AIt was closed on Saturday.
logical-reasoning-s05-q06CIts labelling is undetermined.
logical-reasoning-s05-q07BThe bid was neither late nor incomplete.
logical-reasoning-s05-q08DNeither was the door forced nor the window broken.
logical-reasoning-s05-q09CIt was paid.
logical-reasoning-s05-q10ADevi is not a resident.
logical-reasoning-s06-q01BBoth Amara and Ben
logical-reasoning-s06-q02CThe dictionary
logical-reasoning-s06-q03AThree
logical-reasoning-s06-q04DBarrow
logical-reasoning-s06-q05DPriya ranks either first or second.
logical-reasoning-s06-q06AD
logical-reasoning-s06-q07CKemi
logical-reasoning-s06-q08DIt lies somewhere between second and fourth from the top.
logical-reasoning-s06-q09BThursday
logical-reasoning-s06-q10AFlat 6
logical-reasoning-s07-q01DTimekeeper
logical-reasoning-s07-q02BDrums
logical-reasoning-s07-q03CLeeds
logical-reasoning-s07-q04AOn Priya's right
logical-reasoning-s07-q05BBox 3
logical-reasoning-s07-q06DFloor 1
logical-reasoning-s07-q07ARae
logical-reasoning-s07-q08CWednesday, Thursday, or Friday
logical-reasoning-s07-q09CThe pilot
logical-reasoning-s07-q10APosition 3
logical-reasoning-s08-q01CComplaints would still be arriving if the filter were not working.
logical-reasoning-s08-q02AIncreasing student use is a goal worth pursuing.
logical-reasoning-s08-q03DCompleting the crossing calls for strong swimming.
logical-reasoning-s08-q04BHigh-street demand will resemble demand at the market.
logical-reasoning-s08-q05CThirty lessons are enough preparation to pass.
logical-reasoning-s08-q06BTraffic through the junction fell sharply over the same period.
logical-reasoning-s08-q07AOnly well-prepared singers may have chosen to audition.
logical-reasoning-s08-q08DHow many untreated patients recover within a fortnight?
logical-reasoning-s08-q09DThose who tried the app and gave it up are not markedly less satisfied.
logical-reasoning-s08-q10BIt treats the absence of proof as proof of the opposite.
logical-reasoning-s09-q01BPresenting only two options when others exist
logical-reasoning-s09-q02DTreating the source's standing as evidence for the claim
logical-reasoning-s09-q03AThe conclusion is simply restated as the reason for it.
logical-reasoning-s09-q04CA hasty generalisation from a very small sample
logical-reasoning-s09-q05BMisrepresenting a position to make it easier to attack
logical-reasoning-s09-q06CThat whatever most people prefer is thereby better
logical-reasoning-s09-q07DA slippery-slope claim with no support for the chain of steps
logical-reasoning-s09-q08AAge is treated as evidence of merit.
logical-reasoning-s09-q09CMistaking a shared cause for a direct one
logical-reasoning-s09-q10AA property of each part need not carry over to the whole.
logical-reasoning-s10-q01AThe shipment did not clear customs.
logical-reasoning-s10-q02CDev is not a member of the walking group.
logical-reasoning-s10-q03BIts state cannot be settled from these rules.
logical-reasoning-s10-q04DMarta used the press and is trained.
logical-reasoning-s10-q05DThe reservoir is at least half full.
logical-reasoning-s10-q06AThe pitch was not frozen.
logical-reasoning-s10-q07BThe book did not come from the reference section.
logical-reasoning-s10-q08DIris is not registered.
logical-reasoning-s10-q09BThe south gate is unlocked.
logical-reasoning-s10-q10CThe delivery is late.

Worked explanations

logical-reasoning-s01-q01

When the 'if' half of a rule is satisfied, the 'then' half must follow. Confirming the condition is the most direct way to apply a conditional.

logical-reasoning-s01-q02

A weight of 3.4 kg satisfies the stated condition, so the labelling requirement applies to this parcel. The rule says nothing at all about what lighter parcels carry.

logical-reasoning-s01-q03

A conditional guarantees only that the stated condition brings the stated result, every time. It leaves open whether other causes produce that same result.

logical-reasoning-s01-q04

Ruling out the condition does not rule out the result, because Ravi may leave early for some other reason. This tempting mistake is called denying the antecedent.

logical-reasoning-q5

This is valid modus tollens: if P implies Q, and Q is false, then P must be false.

logical-reasoning-s01-q06

A lapsed subscription would guarantee a dead card, so a working card rules the lapse out. Denying the result of a rule lets you deny its condition.

logical-reasoning-s01-q07

An overnight stay would have required a lamp; since no lamp is displayed and the rule was followed, that overnight stay cannot have happened.

logical-reasoning-s01-q08

The rule promises an amber light when toner runs out, but never claims toner is the only trigger. A result cannot be traced back to one cause unless the rule rules the alternatives out.

logical-reasoning-s01-q09

Adding the fact that no other route to the result exists makes the rule work in both directions, so the result can now be traced back to its only possible cause.

logical-reasoning-s01-q10

Refunds are promised for cancellations, but the rule does not make cancellation the only ground for a refund. Working backwards from a result is safe only when the rule closes off the other routes to it.

logical-reasoning-q1

We only know engineers hold the certification. Not that Priya is an engineer, or that only engineers can hold it. Her role isn't stated.

logical-reasoning-s02-q02

An 'all' statement applies to every member of the group without exception, so anything identified as a harbour tour inherits the rule.

logical-reasoning-s02-q03

A 'no' statement excludes every member of the group, so anything shown to belong to that group inherits the exclusion.

logical-reasoning-s02-q04

In logic 'some' means at least one and leaves the rest of the group open. Everyday speech hints that 'some' excludes 'all', but the statement itself makes no such promise.

logical-reasoning-q4

This is a valid categorical syllogism: if no A are B, and all C are A, then no C are B.

logical-reasoning-s02-q06

Every flat in the block has a balcony, so any subgroup of those flats has balconies too. Naming a subgroup never creates an exception to an 'all' statement.

logical-reasoning-s02-q07

Belonging to the excluded group would make Sunday work impossible, so someone who does work Sundays cannot belong to it.

logical-reasoning-s02-q08

Chain the two statements: the hotel's delegates all fall inside the coach group, and that whole group is excluded from arriving early, so the smaller group inherits the exclusion.

logical-reasoning-s02-q09

Sharing a property does not make two groups overlap, coincide, or exclude one another; all that follows is the shared property itself. Reading more into it is the undistributed-middle mistake.

logical-reasoning-s02-q10

Green tags belong only to serviced machines, so anything unserviced cannot carry one. 'Some are not serviced' guarantees at least one such machine exists.

logical-reasoning-s03-q01

'Must have' marks payment as necessary rather than sufficient. Meeting a necessary condition clears one hurdle and leaves any others standing.

logical-reasoning-s03-q02

A necessary condition works most powerfully in reverse: when the requirement is missing, the result it guards is ruled out.

logical-reasoning-s03-q03

'Only if' states a requirement rather than a guarantee, so satisfying it removes an obstacle without settling whether permission is given.

logical-reasoning-s03-q04

'If and only if' makes the condition both necessary and sufficient, which is the one case where a rule may safely be read in either direction.

logical-reasoning-s03-q05

'Unless' means 'if not': without renewal the closure would be certain, so a stall still trading shows the renewal happened.

logical-reasoning-s03-q06

Necessary conditions filter applicants without selecting them, so something further is still required before the outcome is settled.

logical-reasoning-s03-q07

A sufficient condition is enough on its own, so meeting it settles the result, though it leaves open whether other routes to entry also exist.

logical-reasoning-s03-q08

A failed necessary condition blocks the result outright, whatever else was achieved. It also follows that he cannot have passed the practical, since that would have delivered the certificate.

logical-reasoning-s03-q09

'Only to' identifies a requirement, so anyone who has the result must have met it. The reverse claim, that every signatory gets access, is not stated.

logical-reasoning-s03-q10

A factor that is neither required nor enough carries no deductive weight, so its presence leaves the outcome entirely open.

logical-reasoning-s04-q01

Swapping the two halves and negating both gives the contrapositive, which always says the same thing as the original rule.

logical-reasoning-s04-q02

The converse simply swaps the two halves without negating them, and unlike the contrapositive it is not guaranteed to hold when the original does.

logical-reasoning-q2

Assuming rain caused the closure is the 'affirming the consequent' error. The market could be closed for another reason.

logical-reasoning-s04-q04

Negating both halves produces the inverse of the rule, which does not follow from it. The original is silent about anyone outside the programme.

logical-reasoning-s04-q05

'Only' introduces a requirement rather than a guarantee, so it translates into a rule running from the result back to the condition.

logical-reasoning-q3

The rule only says certified divers wear wetsuits. It doesn't say only certified divers do, so Tomas's status is undetermined.

logical-reasoning-s04-q07

Rewriting the ban as a conditional gives 'if unregistered, then barred', so a vehicle that is not barred cannot be unregistered.

logical-reasoning-s04-q08

Denying the result of a conditional lets you deny its condition, and that valid pattern is known as modus tollens.

logical-reasoning-s04-q09

The rule guarantees passability when the tide is out but does not reserve passability for that case, so the result cannot be read backwards.

logical-reasoning-s04-q10

The contrapositive turns 'not returned' into 'not incomplete', and the item states the rule was applied correctly, so no breach is involved.

logical-reasoning-s05-q01

An 'and' statement asserts each part separately, so denying either part contradicts it outright. Details the statement never mentions are merely unknown, not false.

logical-reasoning-q6

This is a valid disjunctive syllogism: if at least one of two options is true, and one is false, the other must be true.

logical-reasoning-s05-q03

Denying a combined claim means at least one part fails; once the first part is known to hold, the failure must lie with the second.

logical-reasoning-s05-q04

'Neither … nor' denies both items at once, so each one may be denied separately. It gives no explanation for the failures.

logical-reasoning-s05-q05

'But never both' makes the choice exclusive, so confirming one option rules the other out, something a plain 'or' would not license.

logical-reasoning-s05-q06

An inclusive 'or' is satisfied as soon as one option holds, so confirming that option leaves the other entirely open.

logical-reasoning-s05-q07

Denying an 'or' denies both options at once, because a single true option would have made the original claim true.

logical-reasoning-s05-q08

Either trigger on its own would have set a working alarm off, so silence rules both triggers out together.

logical-reasoning-s05-q09

With exactly one option true and two of them eliminated, the remaining option must be the true one.

logical-reasoning-s05-q10

Both parts together guarantee the award, so a missing award with one part satisfied points to the other part failing.

logical-reasoning-s06-q01

'Ahead of' passes along a chain, so anyone ahead of Ben is also ahead of whoever Ben beats.

logical-reasoning-s06-q02

Fixing the top and bottom books leaves two middle slots, and the 'directly above' pair can fill them in only one order.

logical-reasoning-s06-q03

Rita is third, so two people stand ahead of her; Sam is therefore fourth, with Rita and those two ahead of him.

logical-reasoning-s06-q04

One town has a neighbour on each side along the same line, which is exactly what it means to be in the middle.

logical-reasoning-s06-q05

Two named candidates sit above fourth place, and one of that pair sits above the other, which forces the higher of them into the top two.

logical-reasoning-s06-q06

Chaining the two 'immediately behind' clues from the fixed position fills the next two slots in order, landing one of them in fifth place.

logical-reasoning-s06-q07

Linking each comparison end to end produces one complete order from highest to lowest, and third place falls straight out of it.

logical-reasoning-s06-q08

Ruling out the two ends leaves three possible slots, and nothing in the item narrows those three to one.

logical-reasoning-s06-q09

The survey has to come before the report's fixed day, so any later day is impossible while earlier days all remain open.

logical-reasoning-s06-q10

The middle of seven floors is the fourth, since three lie below it and three above; counting two floors up from there gives the answer.

logical-reasoning-s07-q01

One role is taken outright and another is barred, which leaves a single role available for the person under the restriction.

logical-reasoning-s07-q02

Removing both string options and the flute from Ben's list leaves one instrument, so his choice is settled without needing the other pupils.

logical-reasoning-s07-q03

The heaviest parcel is excluded from one city outright, and it cannot be the lightest, which quietly rules out a second city as well.

logical-reasoning-s07-q04

The opposite pair is fixed first, which reserves two sides; naming the left-hand neighbour then leaves only the right-hand side for the last person.

logical-reasoning-s07-q05

Start with the box carrying two exclusions, since it can hold only one colour; the remaining exclusion then decides the other two boxes.

logical-reasoning-s07-q06

Test each position for the linked pair on the three free floors, then discard the arrangement that forces a department onto the floor it is barred from.

logical-reasoning-s07-q07

One order is given outright, and the exclusion removes the coffee from one of the two people left, leaving only one candidate.

logical-reasoning-s07-q08

First narrow the earlier person to the days left open, then shift that whole set one day later for the person who follows.

logical-reasoning-s07-q09

Someone who must have a neighbour above them cannot be on the top floor, and the stated exclusion removes a second candidate, leaving one.

logical-reasoning-s07-q10

Two fixed positions leave a pair of adjacent slots, and the left-to-right clue puts that pair in only one possible order.

logical-reasoning-s08-q01

The argument reads silence as success, which holds only if complaints reliably track the underlying problem.

logical-reasoning-s08-q02

A recommendation supported by an outcome quietly treats that outcome as desirable; without that step the stated reason lends no support at all.

logical-reasoning-s08-q03

The argument moves from an achievement to an ability, a step that works only if the achievement really demands that ability.

logical-reasoning-s08-q04

Generalising from one setting to another requires the two settings to be alike in whichever respect the argument depends on.

logical-reasoning-s08-q05

Supplying the general rule that links the evidence to the conclusion is what turns a bare fact into an argument.

logical-reasoning-s08-q06

A rival explanation for the very same change undercuts the claim that the intervention produced it.

logical-reasoning-s08-q07

A high success rate can reflect who chose to take part rather than how hard the test was, which is a selection effect.

logical-reasoning-s08-q08

Without a comparison group, a recovery rate cannot show that the treatment rather than time made the difference.

logical-reasoning-s08-q09

Asking only the people who stayed leaves out those who left, so the wider claim holds only if the missing group would not change the picture. This blind spot is called survivorship bias.

logical-reasoning-s08-q10

A missing finding is not a finding. Failing to establish a claim leaves the question open rather than settling it the other way.

logical-reasoning-s09-q01

A false dilemma squeezes a range of possibilities into two, hiding middle paths such as shorter hours or a relocated stage.

logical-reasoning-s09-q02

Long service may make someone worth listening to, but it does not by itself make any particular proposal correct.

logical-reasoning-s09-q03

Circular reasoning assumes what it sets out to show, leaving a listener with no independent reason to accept it.

logical-reasoning-s09-q04

Two cases cannot stand in for a town; a claim about a population needs evidence drawn more broadly from it.

logical-reasoning-s09-q05

Recasting a modest proposal as an extreme one attacks a straw man instead of the position actually held.

logical-reasoning-s09-q06

Popularity and quality are separate questions, so an argument crossing from one to the other needs a bridge it has not supplied.

logical-reasoning-s09-q07

Predicting a chain of consequences requires evidence that each link actually follows; without it the alarming end point is asserted rather than shown.

logical-reasoning-s09-q08

An appeal to tradition mistakes how long something has lasted for how well it works, and those are different questions.

logical-reasoning-s09-q09

Warm weather plausibly drives both figures upwards, so their rising together says nothing about one producing the other.

logical-reasoning-s09-q10

Reasoning from parts to whole, the fallacy of composition, fails whenever the property accumulates, and enough light parts make a heavy machine.

logical-reasoning-s10-q01

Chain the two conditionals into a single rule running from customs to restocking, then apply it backwards: a false end result makes the first condition false.

logical-reasoning-s10-q02

The two rules chain into one: every member has trained recently, so failing that test rules membership out.

logical-reasoning-s10-q03

Chained rules run in one direction only, so a true end result does not travel back up the chain unless each step is stated as the sole route.

logical-reasoning-s10-q04

Work forwards from the stated use: the user must appear in the log, only one name is there, and the training rule then applies to that person.

logical-reasoning-s10-q05

Read the chain backwards twice: no signs means the sprinklers are running, and running sprinklers mean the reservoir is not low.

logical-reasoning-s10-q06

The inspection time changes nothing; the two conditionals chain together and are then run backwards from the refund that never happened.

logical-reasoning-s10-q07

Reference books are all catalogued and catalogued books never leave, so anything that left cannot have come from that section.

logical-reasoning-s10-q08

Follow the chain backwards from the missing acknowledgement: no acknowledgement means no pair of references, and without those the registration rule cannot have been satisfied.

logical-reasoning-s10-q09

The unlit security light rules out the north gate through the conditional, and the either-or statement then forces the remaining option to hold.

logical-reasoning-s10-q10

Two conditionals run backwards from the missing notification to rule out an early delivery, and the exclusive either-or then leaves a single option. The closing time plays no part in the deduction.