Which of the following numbers will replace the question mark (?) in the given series?
7, 7, 9, 27, 31, 155,?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3. i.e. 161.
The series follows this pattern:
7 × 1 = 7, 7 + 2 = 9, 9 × 3 = 27, 27 + 4 = 31, 31 × 5 = 155, 155 + 6 = 161