Question

If each of the dimension of a rectangle is increase by 100 % , then the area is increased by

• A. 100%
• B. 200%
• C. 300%
• D. 400%

Answer 1

The correct option is C 300%

Let the length of rectangle is x cm and wight is y cm

Then area of rectangle =xy sq cm

After increase length 100% the length=2x cm

And After increase wight 100% the length=2y cm

Then area of increase rectangle =$2x\times 2y=4xy$ sq cm

Then increase in area of rectangle=4xy-xy=3xy sq cm

% of increase in area of rectangle=$\frac{3xy\times 100}{xy}=300$%