Question

The perimeter of a rectangle is 240 CM if its length is decreased by 10% and breadth is increased by 20% we get the same perimeter find the length and breadth of rectangle

Answer 1

2(l+b)=240
l+b=120
l=120-b
2(.9l+1.2b)=240
.9l+1.2b=120
.9(120-b)+1.2b=120
108-.9b+1.2b=120
.3b=12
b=40
l=80