Question

The radius of a circle is increased by 1%. Find how much % does its area increases?
a)1.01%
b)5.01%
c)3.01%
d)2.01%​

Answer 1

Answer:

d) 2.01%

Let radius of circle = 100 m

New radius = 101 m

original area = [π x (100)2 ]m2

New area = [π x (101)2 ]m2

Increase% = [π x {(101)2 - (100)2} / { π x (100)2} ] x 100 %

= 201 / 100% = 2.01%