Question

The length and width of rectangle are doubled.What is the percentage of increase in area

Answer 1

let the actual length and width be l₁ and w₁
Area₁= l₁w₁
l₂ =2l₁
w₂= 2 w₁
area₂= l₂w₂
area₂= 4l₁w₁
increase in area(area₃) = area₂- area₁
= 3l₁w₁
% in increase in area = area₃/area₁ ×100
= 3l₁w₁/l₁w₁×100
= 300%