Question

In each of the following number series, the wrong number is given, find out that number.

1, 2, 6, 15, 31, 55
1. 1
2. 2
3. 55
4. 16
5. 31

Answer 1

Correct Answer - Option 3 : 55

Calculation∶

The series follows the following pattern

⇒ 1 + 1² = 2

⇒ 2 + 2² = 6

⇒ 6 + 3² = 15

⇒ 15 + 4² = 31

⇒ 31 + 5² = 56

∴ Wrong number of the series is 55