If the side of a square is increased by 25%, by what percentage does its area increase?

The area increases by 56.25%, which is None of the above.

Area of a square = side^2.

New side = 1.25 times the old side.

New area = (1.25)^2 = 1.5625 times the old.

Increase = 1.5625 - 1 = 0.5625 = 56.25%.

Since 56.25% is not listed, the choice is None of the above.