Lateral thinking

A note left on a shared kitchen door.

1. Priya left a note on the kitchen door: “There is a ring on the table and it is yours.”
2. Her housemate Owen owns no jewellery and has lost nothing.
3. Owen drank cocoa at the kitchen table last night and did not use a mat.
4. The table is bare varnished wood, and Priya polishes it every Saturday.
5. Owen's phone shows no missed calls.

One afternoon, told in the order it happened.

1. Ines poured a fresh, steaming cup of tea and set it on her desk.
2. The doorbell rang and she went to answer it.
3. When she sat back down the tea was stone cold.
4. Nobody else entered the flat, nothing was added to the cup, and the heating was on all afternoon.
5. The caller was a neighbour whose boiler had failed; Ines helped her ring an engineer and wait for him.

An extract from a committee meeting.

1. The choir committee has six named posts but only five people sit on it.
2. The minutes read: “The treasurer passed the accounts to the librarian for filing.”
3. During the meeting nobody left their seat and no papers were handed across the table.
4. The accounts are a paper ledger, and there is no computer in the room.
5. The minutes are accurate and nothing has been left out.

An afternoon of moving boxes in a closed library.

1. The library is closed to readers this afternoon and boxes are being carried into the store room.
2. The librarian asks a volunteer to fetch the heaviest book on the trolley.
3. The fire door to the store room swings shut on its own, so the volunteer must put the boxes down every time to open it.
4. Nothing may be screwed or taped to the door or to the walls.
5. There is no draught in the building and every window is shut.

Two entries from the same week of a diary.

1. One flat in Dana's building, flat four, came free in the spring and was taken in May.
2. Monday's entry: “Met the new neighbour from flat four — a tall man who plays the trumpet.”
3. Thursday's entry: “Met the new neighbour from flat four — a short woman who keeps bees.”
4. Both entries are accurate, and Dana never repeats herself.
5. Nobody moved in or out of the building between Monday and Thursday.

An afternoon's rowing on a river.

1. The boathouse and the weir sit on the same river, two kilometres apart.
2. Marek rows out to the weir in forty minutes.
3. He rows back to the boathouse in twenty-five minutes.
4. He pulled just as hard in both directions, and the air was still all afternoon.
5. A stick dropped off the boathouse jetty drifts steadily away from the weir.

Five evenings in a locked office building.

1. After half past five the caretaker is the only person in the building, and the outside doors are locked.
2. At six o'clock each evening she hears a woman's voice call out from the entrance hall.
3. The voice says exactly the same six words at exactly the same minute every evening.
4. She has searched the hall each time and found nobody, and nobody is playing a trick on her.
5. Last month an accessibility system was fitted, with speakers in the ceiling of the entrance hall.

A store cupboard, the morning after a clean.

1. The cupboard holds three identical tins whose printed labels — Flour, Sugar, Rice — are stuck to the lids.
2. Yesterday a helper emptied, washed and dried all three tins, refilled them from the sacks, and put the lids back on.
3. The sacks are open at the top and their contents are plainly visible.
4. The helper checked each tin against its label as he filled it.
5. This morning the cook lifted the lid marked Rice and found sugar underneath.
6. Nothing was taken, nobody moved a label, and nobody played a trick.

One party, described twice.

1. Rosa's account of the party: “We sang, we cut the cake, and Theo arrived.”
2. Rosa's account is truthful and complete.
3. An unaltered photograph taken at that party shows Theo beside the cake, candles lit and the cake whole.
4. There was one cake and it was cut once.

A visitor and a guide, standing side by side.

1. A visitor points at the church and asks how long it takes to walk from there to the top of the fell.
2. The guide says “about four seconds”, and means it.
3. From where they stand, both can see the church, the lane, the river and the whole fell at once without turning their heads.
4. Neither is looking at a screen, a photograph or a printed map, and neither is joking.
5. The guide can reach out and touch the summit.

A landlord and a letting agent, both telling the truth.

1. Eight doors open onto the street along the front of the block.
2. Every flat in the block is let, and none is empty.
3. The letting agent's file lists six tenancies and is complete and correct.
4. No tenant rents two flats, and no flat is split between two tenancies.
5. As well as flats, the block contains a bin store and a stairwell to the upper floors, each reached from the street.

An allotment shed, five mornings running.

1. Farhan locks the shed at dusk with the light off and finds it lit when he arrives at seven the next morning.
2. Only Farhan and his neighbour Delia hold keys, and Delia has been in another country for three weeks.
3. The shed's one window is painted over and does not open.
4. Every morning the rocker switch by the door is still in the off position, and no timer is fitted to it.
5. A month ago Farhan replaced the bulb with a motion-sensing one, and mice have been getting in under the door.

A library photocopier with a very regular fault.

1. The copier jams repeatedly on Monday mornings and works normally from Monday lunchtime until Friday closing.
2. The same staff use it, with the same paper, and it copies roughly the same number of pages every day.
3. The building is unheated from Friday evening until eight o'clock on Monday morning.
4. Paper is stored in an open rack against an outside wall beside the machine.
5. An engineer has stripped the machine twice and found no mechanical fault.

A delivery to a fifth-floor office.

1. The crate is a rigid box 2.05 metres long, 0.4 metres wide and 0.4 metres deep.
2. The lift car measures 2.00 metres wide, 2.00 metres deep and 2.00 metres high.
3. The staircase turns so sharply that nothing longer than 1.6 metres can be carried up it at any angle.
4. The crate arrived on the fifth floor undamaged, unopened and unbent.
5. There is no hoist, no crane, and no way in from outside the building.

A surgery appointment that nobody has a record of.

1. The surgery sends every patient a text on the evening before an appointment, without exception.
2. Priya's phone has kept every message it has received this year and she has deleted none.
3. There is no message from the surgery about Tuesday.
4. Her phone had signal all week and received other messages on Monday evening.
5. Priya arrived on Tuesday and was told there was no appointment in her name.

Eight tomato plants and one new bottle of feed.

1. Sana fed eight tomato plants with a new feed on the first of June, at the strength printed on the bottle.
2. Four of the plants are in her greenhouse and four are in an outdoor bed.
3. By the tenth of June the four in the greenhouse had yellowed; the four outdoors were untouched.
4. The greenhouse's automatic vent jammed shut on the last day of May and was freed on the eleventh of June.
5. She has grown tomatoes in the same greenhouse soil for nine years without losing a plant.

Two years of records from a leisure centre.

1. On days the cafe takes more than four hundred pounds, lost property receives twelve or more items.
2. On quiet cafe days it receives fewer than four.
3. Almost every item handed in is a towel, a pair of goggles or a swimming cap.
4. School galas and lesson blocks run on the same days the cafe is busiest.
5. The two totals have risen and fallen together for two years.

Six facts gathered about one delivery.

1. The delivery docket was signed inside the building at 10:40 on Wednesday.
2. Only four people can get into the building: Nina, Piotr, Ruth and Salim.
3. Nina was on a train between 10:00 and 11:30 on Wednesday.
4. Piotr broke his writing wrist in April and has signed nothing since.
5. Ruth's badge shows she first entered the building at 11:05 on Wednesday.
6. Salim's badge shows he was in the building from 08:30 on Wednesday.

A school trip, ready to leave.

1. The minibus is licensed to carry sixteen passengers plus the driver.
2. Every child on the trip was given exactly one packed lunch.
3. The caterer delivered eighteen packed lunches; all were handed out and none was left over.
4. Two adult helpers are travelling as well, and each was given a packed lunch too.
5. The driver brings his own food and does not count as a passenger.
6. The driver counted heads at the door and refused to set off.

A reading room, found after lunch.

1. The librarian comes back from lunch to find the reading room's fire door propped open with a chair.
2. There is a wet patch on the floor by that door and papers scattered across the room.
3. It has not rained for nine days and the ground outside is dry.
4. The corridor's water cooler has been moved out of its alcove and now stands just outside the fire door.
5. The window at the far end of the reading room is wedged open all summer.

A bicycle rack, Tuesday evening to Wednesday morning.

1. On Tuesday the owner locked her bicycle to the rack with a rigid D-lock and walked away.
2. On Wednesday morning the frame, the front wheel and the saddle are gone.
3. The D-lock is still closed around the rack's rail, with the rear wheel hanging inside it.
4. The lock shows no cut marks and its key has not left her pocket.
5. The rear wheel is held to the frame by a quick-release lever that opens by hand.
6. The rack is bolted down, undamaged, and nothing else in it has been touched.

One evening, minute by minute.

1. Yusuf left his bag on the chair by the window of a cafe he had never visited before, at half past five, and walked straight home, arriving at six.
2. He spoke to nobody on the way and sent no messages.
3. A note in his flatmate's handwriting was on the kitchen table when he arrived, saying his bag was on the chair by the cafe window.
4. The flatmate was in the flat until quarter to six, then went out and has not been back.
5. The flat has no telephone and her mobile has been switched off since noon.

One exchange between two people who each hold half the information.

1. A hall is laid out in equal rows of chairs; the number of rows and the number of chairs in each row are both at least two.
2. Everyone present knows the total number of chairs is either twelve or eighteen.
3. Petra has been told the number of rows, and nobody else has been told it.
4. Quinn has been told the number of chairs in each row, and nobody else has been told it.
5. Petra says: “I cannot work out the total.”
6. Quinn replies: “Before you spoke I could not work it out either, but now I can.”
7. Both speak truthfully, and each knows everything above.

One Saturday at the village hall.

1. The hall has one key; it hangs in a box on the post office wall and every borrower signs it out and back in.
2. The hall was unlocked at nine on Saturday morning and locked again at ten at night.
3. The book records the key out at ten to nine and back at twenty past nine, then out again at twenty-five to ten in the evening and back at twenty past ten.
4. The postmaster is certain the key never left its box on Saturday: he looked at half past nine, at one o'clock and at six o'clock, and it was hanging there each time.
5. No copy exists, the lock was not forced or changed, and the doors cannot be locked or unlocked without the key.

A locked shed, from Friday afternoon to Monday morning.

1. On Monday morning a chalked message was found on the inside of the shed door: “the middle shelf will not hold these boxes”.
2. The shed was locked from Friday evening until Monday morning; the only key was in the grower's pocket throughout, and the shed has no window and no other way in.
3. The boxes were unloaded from a van and carried into the shed on Friday afternoon.
4. Tomas helped that afternoon but left at two o'clock, before the van was opened and before anyone saw how heavy the boxes were.
5. Wren spent the afternoon in the van park and never came within twenty metres of the shed.
6. The grower says he did not write it and had no reason to leave a note for himself.