Sol: Option 3 Explanation: Logic is 2×1 + 1 = 3, 3 × 2 + 4 =10, 10 × 3 + 9 = 39, 39 × 4 + 16 = 172…. So in place of 38, it should be 39.
8 19 52 151 447
1. 19
2. 8
3. 52
4. 447
5. 151
Sol: Option 4 Explanation: The logic is 8 × 3 – 5 = 19, 19 × 3 – 5 = 52, 52 × 3 – 5 = 151. So in place of 447, it should be 448.
4 2 3 7.5 26.75
1. 26.75
2. 7.5
3. 3
4. 2
5. 4
Sol: Option 1 Explanation: Logic is 4 × .5 = 2, 2 × 1.5 = 3, 3 × 2.5 = 7.5, 7.5 × 3.5 = 26.25 In place of 26.75, it should be 26.25.
2 3 10 40 172 885 5346
1. 3
2. 885
3. 40
4. 172
5. 10
Sol: Option 3 Explanation: Logic is 2 × 1 + 1 = 3, 3 × 2 + 4 = 10, 10 × 3 + 9 = 39. Thus the wrong number is 40,it should be 39.
15 18 20 29 45 70 106
1.18
2.20
3.29
4.45
5.70
Sol: Option 1 Explanation: Starting from the back
106– 70 = 36, 70- 45 = 25, 45 – 29 = 16, 29 – 20 = 9, 20 – 16 = 4, 16 – 15 = 1. Every difference is perfect square starting from 36 and decreasing. Thus the wrong number is 18, it should be 16.
Sol: Option 1 Explanation: Logic is that first difference is 3, next difference is 6, 9, so next should be 12 & 15. So instead of 40 the term should be 41
49 50 46 55 38 64 28
1. 49
2. 46
3. 55
4. 38
5. 64
Sol: Option 4 Explanation: Logic is 49 + 1 = 50, 50 – 4 = 46, 46 + 9 = 55, 55 – 16 = 39, 39 + 25 = 64. Thus the wrong number is 38, it should be 39.
Sol: Option 3 Explanation: Logic is 6 × 2 + 3 = 15, 15 × 3 – 4 = 41, 41 × 4 + 5 = 169, 169 × 5 – 6 = 839
Thus the wrong number is 179, it should be 169.
4 6 12 30 90 312.50 1260
1. 6
2. 90
3. 30
4. 12
5. 312.50
Sol: Option 5 Explanation: Logic is 4 × 1.5 = 6, 6 × 2 = 12, 12 × 2.5 = 30, 30 × 3 = 90, 90 × 3.5 = 315, 315 × 4 = 1260. Thus the wrong number is 312.50, it should be 315.
35 19 11 7 5 4.5 3.5
1. 4.5
2. 5
3. 11
4. 19
5. 7
Sol: Option 1 Explanation: 35-19 = 16, 19-11 = 8, 11-7 = 4, 7-5 = 2, 5-4 = 1, 4-3.5 = .5 The difference is halved every time. Thus the wrong number is 4.5, it should be 4.
