Question

A lawn is in the form of a rectangle whose sides are in the ratio 5 : 3. The area of the lawn is 3375m². Find the cost of fencing the lawn at ₹ 65 per metre.

Answer 1

Let the length and breadth of the rectangular lawn be 5x m and 3x m, respectively.

Given:

Area of the rectangular lawn = 3375 m²

\(\Rightarrow\) 3375 = \(5x \times 3x\)

\(\Rightarrow\) 3375 = 15x²

\(\Rightarrow\) \(\frac{3375}{15}=x^2\)

\(\Rightarrow\) 225 = x²

\(\Rightarrow\) x = 15

Thus, we have:

Perimeter of the rectangular lawn = \(2(l+b)\)

= 2(75 + 45)

= 2(120)

= 240 m

Cost of fencing 1 m lawn = Rs 65

∴ Cost of fencing 240 m lawn = 240 x 65 = Rs 15,600