In following question, a number series is given with one term missing. Choose the correct alternative that will same pattern and fill in the blank spaces. -
21, 25, 33, 49, 81,
Answer: A. 145
The pattern is + 4, + 8, + 16, + 32,.... i.e. + 22, + 23, + 24, + 25,...
.'. Missing number = 81 + 26 = 81 + 64 = 145.