.
The perimeter of rectangle is 240cm if it's length decreased by 1o% and the breadth is increased by 20% we get the same perimeter.
Find the original length and breadth of the rectangle
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
x + y = 120, (1) ( 120 = )
0.9x + 1.2y = 120. (2)
Multiply eq. (1) by 0.9 and distract from the eq. (2). You will get
0.3y = 120 - 108,
0.3y = 12,
y = = 40.
Answer. The width was 40 cm, the length was 120 - 40 = 80 cm.