1.  Choose the correct alternative that will continue the same pattern and replace the question mark in the given series : 1, 5, 13, 25, 41, ?

A. 51
B. 57
C. 61
D. 63

Answer: Option C

Explanation:

The pattern is +4, +8, +12, +16,.... so, missing term = 41 + 20 =61.