If the side of a square is increased by 25 %. Then its area is increased by:__________?

A. 25 %
B. 55%
C. 40.5 %
D. 56.25 %
Explanation:
Let the side of the square be x units.
Then it’s area = x2 sq. Units
Side of new square = 125 % of x = (125/100 × x)units = 5x/4 units
New area = (5x/4 × 5x/4)sq.units = 25×2/16 Sq.units
Increase in area = (25×2/16 – x2) = 9×2/16 Sq.Units
Increase % = (9×2/16 × 1/x2 × 100)%
= 225/4 % = 56.25 %