Mensa IQ Test Mensa IQ Numerical Pattern Recognition Questions and Answers 2 — Questions and Answers

Question 1: What is the missing number? 2, 6, 12, 20, 30, ?

40
42 (Correct answer)
44
48

Correct answer: 42

Differences: 4, 6, 8, 10, 12. The pattern is consecutive even differences. 30+12=42.

Sequence: 2, 6, 12, 20, 30. First differences: 4, 6, 8, 10 (increasing by 2). Next difference = 12. So 30 + 12 = 42. Alternatively: terms are n(n+1): 1×2=2, 2×3=6, 3×4=12, 4×5=20, 5×6=30, 6×7=42.

Question 2: Find the missing number: 1, 4, 9, 16, 25, ?, 49

30
36 (Correct answer)
38
42

Correct answer: 36

These are perfect squares: 1²=1, 2²=4, 3²=9, 4²=16, 5²=25, 6²=36, 7²=49.

The sequence is squares of natural numbers: 1²=1, 2²=4, 3²=9, 4²=16, 5²=25, 6²=36, 7²=49. The missing number is 6² = 36.

Question 3: What replaces the ? [Row 1: 3, 5, 8] [Row 2: 4, 7, 11] [Row 3: 6, 9, ?]

13
15 (Correct answer)
16
18

Correct answer: 15

In each row, the third number equals the first plus the second. Row 3: 6+9=15.

Row 1: 3+5=8. Row 2: 4+7=11. Row 3: 6+9=15. The rule is that the third number in each row equals the sum of the first two numbers.

Question 4: Which number does not belong in this series? 2, 3, 5, 7, 11, 14, 13, 17

5
7
14 (Correct answer)
13

Correct answer: 14

All other numbers are prime. 14 = 2×7, so it is composite and does not belong.

Prime numbers: 2 ✓, 3 ✓, 5 ✓, 7 ✓, 11 ✓, 14 ✗ (14=2×7, composite), 13 ✓, 17 ✓. The non-prime intruder is 14.

Question 5: Identify the rule and find the next term: 100, 50, 25, 12.5, ?

5
6.25 (Correct answer)
8
10

Correct answer: 6.25

Each term is halved: 100÷2=50, 50÷2=25, 25÷2=12.5, 12.5÷2=6.25.

This is a geometric sequence with common ratio 1/2. Each term is divided by 2: 100→50→25→12.5→6.25. The next term is 12.5 ÷ 2 = 6.25.

Question 6: What is the missing number in this sequence? 0, 1, 3, 6, 10, 15, ?

18
19
21 (Correct answer)
22

Correct answer: 21

These are triangular numbers. Differences: 1, 2, 3, 4, 5, 6. Next: 15+6=21.

Triangular numbers: T(n) = n(n+1)/2. T(0)=0, T(1)=1, T(2)=3, T(3)=6, T(4)=10, T(5)=15, T(6)=21. Differences increase by 1 each time: 1, 2, 3, 4, 5, 6. Next term: 15+6=21.

Mensa IQ Test Mensa IQ Numerical Pattern Recognition Questions and Answers 2

What is the missing number? 2, 6, 12, 20, 30, ?

Select your answer