Which one of the following is a perfect square 279 169 154 115

The answer is 169.

169 is a perfect square since 13 times itself (or 13²) is equal to 169.

√279=16.703

√169=13

√154=12.41

√115=10.72

A perfect square is a number that can be formed when two other integers are multiplied by each other. For example 2 times 2 is 4 therefore 4 is square number.

In this case 13 times 13 is 169 which makes it a square number.