Question

The area of rectangular park is 2160sq.m the length and breath is ratio 5:3 find the cost of fencing the park at Rs.5 per metre

Answer 1

Answer: Rs 960

Step-by-step explanation:

Given,

Area of the rectangular park = 2160 sq.m

Ration of length and breadth = 5:3

Let be x. So,

Length = 5x and Breadth = 3x

We know that

L x B = Area

Or, 5x X 3x = 2160

Or, 15x^2 = 2160

Or, x^2 = 2160/15 = 144

Or, x = $\sqrt144$

         = 12

So length = 12x5 = 60m and breadth = 3x12 = 36m.

Perimeter = 2 ( L+B )

= 2 ( 60+36 )

= 2 x 96 = 192 m

Cost at fencing per metre = Rs 5

Total cost = 5 x 192 = Rs 960 ( ans )

Hope this helped

Answer 2

Step-by-step explanation:

Let the length be 5x

let breadth be 3x

l × b = area of rectangle

5x × 3x = 2160

$15{x}^{2} = 2160 \\ {x}^{2} = \frac{2160}{15} \\ {x}^{2} = 144 \\ x = \sqrt{144 } \\ x = 12$

length = 5x = 5 × 12 = 60 m

breadth = 3x = 3 × 12 = 36 m

Perimeter = 2(l + b)

= 2(60 + 36)

= 2(96) = 192 m

For 1 m, cost = Rs 5

For 192m, cost = Rs 5 × 192

= Rs 960