Which of the following numbers will replace the question mark (?) in the given series?
13, 21, ?, 69, 133
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2, i.e., 37.
13 + 8 = 21, 21 + 16 = 37, 37 + 32 = 69, 69 + 64 = 133