Question

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

 7, 21, 45.5, 83, 143.5
1. 7
2. 45.5
3. 143.5
4. 83
5. None of the above

Answer 1

Correct Answer - Option 4 : 83

Calculation∶

The series follows following pattern

3.5 × 1² + 3.5 = 7

3.5 × 2² + 7 = 21

3.5 × 3² + 14 = 45.5

3.5 × 4² + 28 = 84

3.5 × 5² + 56 = 143.5

∴ The wrong number in the series is 83