Mensa IQ Test Mensa IQ Sequence Completion 1 — Questions and Answers
Question 1: What comes next in the sequence: 2, 6, 18, 54, ___?
- 162 (Correct answer)
- 108
- 72
- 216
Correct answer: 162
Each number is multiplied by 3 to get the next: 2×3=6, 6×3=18, 18×3=54, 54×3=162. This is a geometric sequence with a common ratio of 3.
Question 2: Complete the sequence: 1, 1, 2, 3, 5, 8, 13, ___?
- 21 (Correct answer)
- 18
- 20
- 26
Correct answer: 21
This is the Fibonacci sequence where each number is the sum of the two preceding numbers: 5+8=13, 8+13=21. The Fibonacci sequence appears frequently in nature and mathematics.
Question 3: What number completes the sequence: 3, 7, 15, 31, 63, ___?
- 127 (Correct answer)
- 95
- 126
- 64
Correct answer: 127
Each term follows the pattern: multiply by 2 and add 1. 3×2+1=7, 7×2+1=15, 15×2+1=31, 31×2+1=63, 63×2+1=127. Alternatively, these are 2^n - 1 for n = 2, 3, 4, 5, 6, 7.
Question 4: Complete the sequence: 1, 4, 9, 16, 25, ___?
- 36 (Correct answer)
- 30
- 35
- 49
Correct answer: 36
These are perfect squares: 1², 2², 3², 4², 5², so the next is 6² = 36. Recognizing square numbers is a fundamental pattern in IQ-type sequence problems.
Question 5: What comes next: 2, 3, 5, 7, 11, 13, ___?
- 17 (Correct answer)
- 15
- 16
- 19
Correct answer: 17
This is the sequence of prime numbers — numbers divisible only by 1 and themselves. After 13, the next prime is 17. The number 15 (3×5) and 16 (2⁴) are composite.
Question 6: Complete the sequence: 1, 8, 27, 64, 125, ___?
- 216 (Correct answer)
- 150
- 196
- 256
Correct answer: 216
These are perfect cubes: 1³, 2³, 3³, 4³, 5³, so the next is 6³ = 216. Perfect cube recognition is a key numerical reasoning skill tested in Mensa assessments.
Mensa IQ Test Mensa IQ Sequence Completion 1
What comes next in the sequence: 2, 6, 18, 54, ___?