Mensa IQ Test Numerical Reasoning 2 — Questions and Answers

Question 1: What number comes next in the series: 3, 6, 12, 24, 48, ?

72
96 (Correct answer)
84
64

Correct answer: 96

Each term is doubled: 3×2=6, 6×2=12, 12×2=24, 24×2=48, 48×2=96.

This is a geometric sequence with a common ratio of 2. Each term is multiplied by 2 to get the next term. Starting from 3: 3→6→12→24→48→96. The answer is 96.

Question 2: If 5 workers complete a task in 8 days, how many days will 10 workers take to complete the same task?

16
3
4 (Correct answer)
8

Correct answer: 4

Total work = 5×8 = 40 worker-days. With 10 workers: 40÷10 = 4 days.

This is an inverse proportion problem. Total work = 5 workers × 8 days = 40 worker-days. With 10 workers, time = 40 ÷ 10 = 4 days. Doubling the workforce halves the time.

Question 3: What is the missing number in the matrix? [4, 9, 16] [25, 36, 49] [64, ?, 100]

72
81 (Correct answer)
85
78

Correct answer: 81

The matrix contains perfect squares: 2²=4, 3²=9, 4²=16, 5²=25, 6²=36, 7²=49, 8²=64, 9²=81, 10²=100.

Reading the matrix left-to-right, top-to-bottom: 4=2², 9=3², 16=4², 25=5², 36=6², 49=7², 64=8², ?=9²=81, 100=10². The missing number is 81.

Question 4: A train travels 150 km in 2.5 hours. At the same speed, how far will it travel in 4 hours?

200 km
220 km
240 km (Correct answer)
250 km

Correct answer: 240 km

Speed = 150÷2.5 = 60 km/h. Distance in 4 hours = 60×4 = 240 km.

Speed = distance ÷ time = 150 km ÷ 2.5 hours = 60 km/h. In 4 hours: distance = 60 km/h × 4 h = 240 km.

Question 5: What is the next number in the series: 1, 1, 2, 3, 5, 8, 13, ?

18
19
20
21 (Correct answer)

Correct answer: 21

This is the Fibonacci sequence: each term is the sum of the two preceding terms. 8+13=21.

The Fibonacci sequence: 1, 1, 2 (1+1), 3 (1+2), 5 (2+3), 8 (3+5), 13 (5+8), 21 (8+13). The pattern is that each number equals the sum of the two numbers before it.

Question 6: If a rectangle has a perimeter of 36 cm and its length is twice its width, what is the area of the rectangle?

72 cm² (Correct answer)
81 cm²
96 cm²
108 cm²

Correct answer: 72 cm²

Perimeter = 2(l+w) = 36, so l+w = 18. With l=2w: 3w=18, w=6, l=12. Area = 12×6 = 72 cm².

Let width = w, length = 2w. Perimeter = 2(2w + w) = 6w = 36, so w = 6 cm and l = 12 cm. Area = length × width = 12 × 6 = 72 cm².

Mensa IQ Test Numerical Reasoning 2

What number comes next in the series: 3, 6, 12, 24, 48, ?

Select your answer