What should come in place of the question mark '?' in the following number series?
12, 6, 9, 22.5, ?
Show answer & explanation
Correct answer: C
Explanation
Series: 12, 6, 9, 22.5, ?
12 × 0.5 = 6
6 × 1.5 = 9
9 × 2.5 = 22.5
Multipliers are increasing by 1: (0.5, 1.5, 2.5, …)
So, next multiplier = 3.5
22.5 × 3.5 = 78.75
Hence, the correct answer is option 3.