Practice Lab · Rule induction and sequences

Rule induction and sequences

Spot the governing rule in number and symbol sequences.

Untimed instructional practice for the Novus Reasoning Challenge. Explanations teach the reasoning process. These items are not unseen scored-form questions and do not produce an IQ score.

1. 2, 4, 8, 16, ?
2. 3, 6, 12, 24, ?
3. 5, 10, 20, 40, ?
4. 7, 11, 15, 19, ?
5. 100, 91, 82, 73, ?
6. 1, 4, 9, 16, ?
7. 2, 6, 18, 54, ?
8. 81, 27, 9, 3, ?
9. 4, 7, 13, 25, ?
10. 1, 1, 2, 3, 5, ?
11. 10, 20, 15, 30, 25, ?
12. 2, 3, 5, 8, 12, ?
13. 64, 32, 16, 8, ?
14. 0, 3, 8, 15, ?
15. 9, 18, 36, 72, ?
16. 11, 22, 44, 88, ?
17. 5, 6, 9, 14, 21, ?
18. 3, 9, 27, 81, ?
19. 50, 45, 40, 35, ?
20. 1, 2, 4, 7, 11, ?

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Consent version 2026-07-31.1

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