Question

The perimeter of a rectangle is 240cm. If length is decreased by 10% and its breadth is increased by 20% we get the same perimeter. Find the length and breadth of the rectangle.
.

Answer 1

Let the dimensions of the

rectangle are

i) length = x cm

breadth = y cm

Perimeter = 240 cm ( given )

2( x + y ) = 240

x + y = 120 ----( 1 )

If length is decreased by 10% and

breadth is increased by 20% then

the new dimensions are

Length = x ( 100-10)/100

= 90x /100

= 9x /10

Breadth = y× ( 100 +20 )/100

= 120y /100

= 12y /10

Perimeter = 240 cm

2 [ 9x /10 + 12y /10 ] = 240

9x + 12y = 1200

Divide each term with 3

3x + 4y = 400-----( 2 )

Multiply equation ( 1 ) with 3 and

Subtract from ( 2 )

y = 40

Put y = 40 in ( 1 )

x = 80


Therefore ,

Required rectangle dimensions are

Length = x = 80 cm

Breadth = y = 40 cm

I hope this helps you.

****

Answer 2

this is your answer in attachment

please mark my answers as brainliest