Question

In the following number series, one term does not fit into the series. Find the wrong term.

$3,4,15,16,25,36,63,\mathrm{64.....}$

• A. $15$
• B. $16$
• C. $25$
• D. $36$

Answer 1

The correct option is C $25$

By changing $25$ to $35$, we have

$2^2-1,2^2,4^2-1,4^2,6^2-1,6^2,8^2-1,8^2$

Two alternative sequences exist.

Hence, $25$ does not fit into the series.