The side of a square is increased from 20cm to 21cm. Calculate the percentage increase in its area
-
A.
2.5% -
B.
9.3% -
C.
10.0% -
D.
10.25%
Correct Answer: Option D
Explanation
old area = 202 = 400
new area = 212 = 441
% increase in area (=frac{41}{400}times frac{100}{1}\
=10.25%)