Question

What will come in place of (?) in the following number series?

3, 6, 12, 21, ?

1. 36
2. 26
3. 33
4. 40
5. 29

Answer 1

Correct Answer - Option 3 : 33

Given:

The number series:

3, 6, 12, 21, ?

Concept:

Number series following a fixed pattern.

Calculation:

The given number series follows the pattern:

3 + (3 × 0) = 3

3 + (3 × 1) = 3 + 3 = 6 

6 + (3 × 2) = 6 + 6 = 12

12 + (3 × 3) = 12 + 9 =21

21 + (3 × 4) = 21 + 12 = 33

∴ The missing number in the given number series is 33.