Question

Any genius out there to solve this?

which is the missing number in the sequence below?
5,6,9,15,?,40

Answer 1

Answer: 25!

Explanation:

5, 6, 9, 15, ?, 40

5 + 1 = 6

6 + 1 + 2 = 6 + 3 = 9

9 + 1 + 2 + 3 = 9 + 6 = 15

15 + 1 + 2 + 3 + 4 = 15 + 10 = 25

25 + 1 + 2 + 3 + 4 + 5 = 25 + 15 = 40

Answer 2

25

Explanation:

The pattern is + 1, + 3, + 6,... i.e. + 1, + (1 + 2), + (1 + 2 + 3),...

.'. Missing number = 15 + (1 + 2 + 3 + 4) = 25.