Question

The length and the breadth of a rectangular field are in the ratio 5 : 4 and its area is 3380 $m^2$. Find the cost of fencing it at the rate of Rs 75 per m.

Answer 1

Ratio in length and breadth =5 : 4

Area of rectangular field $=3380m^2$

$\therefore$ Let length =5x and breadth =4x

$\therefore 5x\times 4x=3380$

$\Rightarrow 20x^2=3380$

$\Rightarrow x^2=\frac{3380}{20}$

$=169=(13{)}^2$ $\therefore x=13$

$\therefore$ Length $=13\times 5=65m$

Breadth =$13\times 4=52m$

$\therefore$ Perimeter =(l +b)

$=2\times (65+52)m$

$=2\times 117=234m$

Rae of fencing =Rs 75 per in

$\therefore$ Total cost =$234\times Rs75$

=Rs 17550