The percentage increase in the area of rectangle , if each of its side is increased by 10% is?
Choose the correct choice from the following choices:
A) 21 %  B) 30 %  C) 25 %  D) 40 %  E) 50 %

Rationale: "let original length = x meters original breadth = y meters original area = xy m ^ 2 new length = 110 x / 100 new breadth = 110 y / 100 = 11 y / 10 new area = 11 x / 10 * 11 y / 10 = 121 xy / 100 m ^ 2 increase percent = 21 xy / 100 * 1 / xy * 100 = 21 % answer is a"
Answer: A