Question

the l and b of an rectangular park are in ratio 5:4 and its area is 2420 m square ,find the cost of fencing park at rate of ₹10 per m.​

Answer 1

Area of Rectangular Field=2420 m²

L and B Ratio=5:4

Let Ratio=5x,4x

Area=Length×Breadth

5x×4x=2420

20x²=2420

$x {}^{2} = \frac{2420}{20} \\ \\ x {}^{2} = \frac{\cancel{2420}}{\cancel{20}} \\ x {}^{2} = 121 \\ \\ x = \sqrt{121 } \\ \\ x = 11$

We got X=11 m

Length=5x=5×11=55 m

Breadth=4x=4×11=44 m

To fence Around It Find Length of Boundary (Perimeter)

Perimeter=2(l+b)

=2(55+44)

=2×99

=198 m

Cost=₹10 per/m

Total Cost

=198×10

=₹1980