1.  In each of the following questions, one term in the number series is wrong. Find out the wrong term.
5, 10, 40, 80, 320, 550, 2560

A. 80
B. 320
C. 550
D. 2560

Answer: Option C

Explanation:

The correct pattern is × 2, × 4, × 2, × 4, ........ So, 550 is wrong and must be replaced by ( 320 × 2 ) i. e. 640.