A rectangle has 15 cm as its length and 150 cm² as its area :

A rectangle has 15 cm as its length and 150 cm² as its area. It’s area becomes to 4/3 times of the original area by  increasing only its length. Its new perimeter is:

  1. 60 cm
  2. 70 cm
  3. 90 cm
  4. 80 cm
Anurag Mishra Professor Asked on 28th February 2016 in Maths.
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1 Answer(s)

Answer: (3) 90 cm 

Solution:-
The length of a rectangle = 15 cm
The are of the rectangle = 150 cm^2
Then, width of a rectangle = 150/15
= 10 cm

It area becomes to 4/3 times of the original area increasing by only length.
Then. the new area of the rectangle = 150 = 150 X 4/3
= 150 + 200
= 350 cm^2

Sp, length of the new rectangle = 350/10
= 35 cm

Then, the perimeter of new rectangle = 2 (35 + 10)
= 2 x 45
= 90 cm

Hence, the correct answer is option (3) 90 cm.

Anurag Mishra Professor Answered on 5th March 2016.
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