Question

The perimeter of a rectangle is 240cm. If its 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.
(a) 40 cm, 80 cm (b) 80 cm, 40 cm
(c) 60 cm, 60 cm (d) 100 cm, 20 cm
pl gys i need correct answer​

Answer 1

Answer:

option B 80cm,40cm

Step-by-step explanation:

Answer 2

Answer:

b) 80 cm , 40 cm

Step-by-step explanation:

Perimeter of the rectangle given = 240cm

Let x cm be the length of the rectangle,

Let y cm be the breadth of the rectangle,

According to the question:

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= x+ 10÷ 100 x

= 100x + 10x

100

= 110x

100

= 11x

10

And the new breadth be = y− 20 y ÷ 100

= 100y−20y/ 100

= 80y/100

= 8y÷ 10

With new length and breadth we get same perimeter.

So,

⇒2( 1011 x+ 108 y)=240

⇒ 1011 x+ 108

y=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=80 cm

and Breadth=y=40 cm