Which number replaces the question mark?

Which number replaces the question mark?

A 6

B 9

C 8

D 12

Solution

Correct Answer: Option A

Here, 6 - 4 = 2
9 - 6 = 3, 3 - 2 = 1
19 - 9 = 10, 10 - 3 = 7, 7 - 1 = 6

Correct answer is 6.