which is a perfect square?\n121\n140\n168\n195

Explanation:

Step1: Recall perfect - square definition

A perfect square is a number that can be written as the product of an integer with itself.

Step2: Check each option

For 121, $\sqrt{121}=11$ since $11\times11 = 121$. For 140, $\sqrt{140}\approx11.83$ (not an integer). For 168, $\sqrt{168}\approx12.96$ (not an integer). For 195, $\sqrt{195}\approx13.96$ (not an integer).

Answer:

121