IMO Practice Test — Number Patterns
6 Questions • 10 min • Olympiad level
10:00
Question 1 of 6
hard
Starting at 96 and halving each time, what is the 4th term?
12
24
6
48
Explanation: 96, 48, 24, 12 → 4th term is 12.
Question 2 of 6
hard
What comes next: 1, 1, 2, 3, 5, __?
8
7
6
10
Explanation: Add the two before (Fibonacci): 3 + 5 = 8.
Question 3 of 6
medium
What comes next: 1, 3, 6, 10, __?
15
13
14
16
Explanation: Add 2, then 3, then 4, then 5 → 10 + 5 = 15.
Question 4 of 6
hard
Input 1 gives 4, input 2 gives 7, input 3 gives 10. If input is 5, output is…
16
13
15
19
Explanation: Rule is × 3 + 1, so 5 × 3 + 1 = 16.
Question 5 of 6
hard
Output is 25 when the rule is 'multiply by 5'. The input was…
5
20
30
125
Explanation: 25 ÷ 5 = 5.
Question 6 of 6
hard
What comes next: 90, 79, 68, 57, __?
46
47
45
48
Explanation: Subtract 11 each time → 46.