Question

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

Answer 1

Answer:

So,

$length = x = 80cm \\ and \\ breadth = y = 40cm$

Step-by-step explanation:

Perimeter of right angle given = 240 cm

let

$x \: \: cm$

• the length of the rectangle Y CM be the breadth of the rectangle

A/Q

2(x+y)=240

⇒x+y=120 [First equation]

Now, its length is increased by 10% and its breadth is decreased by 20%

So, the new length be= 10/100x

= 100x+10x/100

=110x/100

=11x/10

• And the new breadth be = y− 20/100y

= 100y-20y/100

=80y/100

=8y/10

• With new length and breadth we get same perimeter.

So,

⇒2(11/10*+8/10y) =240

⇒11/10*8/10y =120

⇒11x+8y=1200 [Second equation]

• Now, Second equation −8× [First equation], we get

3x=240

⇒x=80

• Putting this value isn First equation,
• y=120−80=40

So, length =x =80cm

& breadth = y= 40 cm