Discussion of Question with ID = 072 under Areas

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Question

The length and breadth of a rectangular area are in the ratio 5 : 3. What is the length of the field if a car travelling at 12 km/h covers one round of the rectangle in 320 minutes?

A

20 km.

B

22 km.

C

18 km.

D

24 km.

Soln.
Ans: a

Let L = 5x and B = 3x. Perimeter = 2 × (5x + 3x) = speed × time = (12 × 320)/60 = 64 km. So x = 4, and L = 5x = 20 km.

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