math
posted by mika on .
The lenght and the width of a rectangle are in the ratio 3:2. If the lenght is increased by 20 and the width is decreased by 5, the ratio of the lenght to the width becomes 2:1. Find the lenght and width of this rectangle.

l/w=3/2
or w=2l/3
(l+20)/(w5)=2
l+20=2w10
l+20=4l/3 10
1/3 l=30
l=90
w=60