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