Question

The length and breadth of a rectangle are in the ratio $2:1$. If the area of the field is $72$ sq.m, find the cost of fencing the field with barbed wire at the ratio of Rs $15$ per metre.

Answer 1

Given length and breadth of a rectangle are in the ratio $2:1$

let breadth of a rectangle is $x$

$\Rightarrow$ length of rectangle is $2x$

Given area $=72sq.m$

$\Rightarrow$ Area of a rectangle $=$ length $\times$ breadth

Area $=2x^2$

$72=2x^2$

$x=6$

$\therefore$ Length $=2x=12$

breadth $=x=6$

$\Rightarrow$ Perimeter of rectangle $=2(l+b)$

$=2(12+6)$

$=36m$

$\Rightarrow$ Cost of fencing per meter $=Rs.15$ per meter

$\Rightarrow$ Cost of fencing per $36$meters$=36\times 15$

$=Rs.540$