Question

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,

• A. 145
• B. 129
• C. 113
• D. 97

Answer 1

The correct option is A 145

The pattern is + 4, + 8, + 16, + 32,.... i.e. +$2^2,+2^3,+2^4,+2^5,...$
$\therefore$ Missing number = $81+2^6=81+64=145.$