If the radius of a circle is increased by 12% then its area increases by:
- A24%
- B25.44%
- C12%
- D12.72%
Solution & Step-by-step Explanation
Area of a circle is given by A=πr
2
.
When a dimension increases by x%, the net percentage increase in its square (area) is given by the successive percentage formula:
Percentage Increase=x+x+
100
x×x
Given x=12:
Percentage Increase=12+12+
100
12×12
=24+
100
144
=24+1.44=25.44%
2
.
When a dimension increases by x%, the net percentage increase in its square (area) is given by the successive percentage formula:
Percentage Increase=x+x+
100
x×x
Given x=12:
Percentage Increase=12+12+
100
12×12
=24+
100
144
=24+1.44=25.44%