Correct Answer - Option 5 : 40

**Given:**

The number series:

10, 11, 15, 24, ?, 65

**Concept Used:**

Number series following a fixed pattern.

**Calculation;**

The given number series follows the pattern:

10 + 1^{2} = 11

11 + 2^{2} = 15

15 + 3^{2} = 24

24 + 4^{2} = 40

40 + 5^{2} = 65

**∴**** The number in place of “?” in the given number series is 40**