Question

What is the percentage increase in the area of a rectangle, if each of its sides is increased by 20%?

Answer 1

Initial length = l
         breadth=b
         area=lb
Final length = 20l/100+l=l+5l/5=6l/5
         breadth=20b/100+b=6b/5
         area=6l/5X6b/5=36lb/25
Increase in area= 36lb/25-25lb/25=11lb/25
%Increase= 11lb/25/lb X100= 44lb/lb=44%