Question

Which of the following is a perfect square? A 169 B 279 C 154 D 115

Answer 1

Answer: 169.

Justification.

A perfect square is a number that can be expressed and the square of an integer.

$169=13^2=13*13$

It is a good idea to memorize the first perfect squares. I sugest you memorize the squares of the numbers from 1 to 14, it will help you a lot in some standardized tests,which requires to answer some quesitons fast:

$1^2=1 2^2=4 3^2=9 4^2=16 5^2=25 6^2=36 7^2=49 8^2=64 9^2=81 10^2=100 11^2=121 12^2=144 13^2=169 14^2=196$

Answer 2

A.

 $\sqrt{169}$  = 13
Check: 13 x 13 = 169, therefore 13 is a perfect square