1.  In each of the following questions, one term in the number series is wrong. Find out the wrong term.
1, 3, 12, 25, 48

A. 3
B. 12
C. 25
D. 48

Answer: Option C

Explanation:

The terms of the series are ( 1² - 0² ), ( 2² - 1² ), (4² - 2² ), (6² - 3²), and ( 8² - 4² ). So, 25 is wrong and must be replaced by ( 6²- 3² ) i.e. 27.