If radius of a circle is increased by 5%, then the increase in it's area is :

A. 10.25%

B. 5.75%

C. 10%

D. 5%

Answer: Option A

Solution(By Examveda Team)

Quicker approach
$$ \uparrow $$   in A = a + b + $$\frac{ab}{100}$$
Here a = b = 5%
$$ \uparrow $$   in A :
$$\eqalign{ & = \left( {5 + 5 + \frac{{5 \times 5}}{{100}}} \right)\% \cr & = 10.25\% \cr} $$