Perimeter of rectangle is 240cm if it's length is decreased by 10 percent and breadth is increased by 20 percent we get the same perimeter find the length and breadth of the rectangle

Answer 1

x+y=120
0.9x + 1.2y = 120

80+40 = 120
72+48 = 120

Answer 2

width --- w
length --- l

2l + 2w = 240
l + w = 120 ---- l = 120-w **

new width = 1.2w
new length = .9l

2(1.2w) + 2(.9l) = 240
2.4w + 1.8l = 240
24w + 18l = 2400
divide by 6
4w + 3l = 400
sub in **
4w + 3(120-w) = 400
4w + 360 - 3w = 400
w = 40
then in ** , l = 80

the original rectangle was 40 cm by 80 cm

check: Perimeter = 2(40) + 2(80) = 240

changed rectangle was 48 by 72
perimeter of changed rectangle
= 2(48) + 2(72) = 240