Mensa IQ Test Mensa IQ Numerical Reasoning and Arithmetic 4 — Questions and Answers
Question 1: What number comes next: 5, 10, 20, 35, 55, [?]?
- 80 (Correct answer)
- 75
- 85
- 70
Correct answer: 80
Differences are 5, 10, 15, 20, 25 (arithmetic sequence with +5 each time); 55 + 25 = 80.
Question 2: A missing-number grid: [8, 4, 2] and [12, 6, 3] and [20, 10, ?]. What is the missing value?
- 5 (Correct answer)
- 4
- 6
- 8
Correct answer: 5
Each row is halved at each step (8→4→2; 12→6→3; 20→10→5), so the missing value is 5.
Question 3: If 5 cats catch 5 mice in 5 minutes, how many minutes will it take 100 cats to catch 100 mice?
- 5 (Correct answer)
- 100
- 20
- 10
Correct answer: 5
Each cat catches 1 mouse in 5 minutes; 100 cats each catch 1 mouse → 100 mice in 5 minutes.
Question 4: What replaces [?] in the series: 2, 5, 11, 23, 47, [?]?
- 95 (Correct answer)
- 89
- 97
- 91
Correct answer: 95
Each term = 2 × previous + 1: 2×2+1=5, 2×5+1=11, 2×11+1=23, 2×23+1=47, 2×47+1=95.
Question 5: A school has 600 students. 40% play sports, 35% study music, and 15% do both. How many students do neither?
- 240 (Correct answer)
- 180
- 300
- 120
Correct answer: 240
Sports OR Music = 40+35−15 = 60%; neither = 40%; 40% of 600 = 240.
Question 6: A sequence of fractions: 1/2, 2/3, 3/4, 4/5, [?]
- 5/6 (Correct answer)
- 4/6
- 6/7
- 5/5
Correct answer: 5/6
The numerator and denominator each increase by 1 per step, giving n/(n+1); the 5th term is 5/6.
Question 7: In a number triangle, each number equals the sum of the two numbers directly above it. Bottom row: 1, 3, 3, 1. Second row: 4, 6, 4. Third row: 10, [?]. What is the missing value?
- 10 (Correct answer)
- 14
- 8
- 12
Correct answer: 10
Third row: 4+6=10 and 6+4=10; the second value in the third row is also 10.
Mensa IQ Test Mensa IQ Numerical Reasoning and Arithmetic 4
What number comes next: 5, 10, 20, 35, 55, [?]?