Question

The length and breadth of a rectangular field are in the ratio $7:4$. The cost of fencing the field at $Rs.25$ per metre is $Rs.3300$. Find the length (in m) of the field.

Answer 1

Let length of rectangle be x m

Raito of length and Breadth$=7:4$

$\frac{x}{Breadth}=\frac{7}{4}$

$\Rightarrow$ Breadth$=\frac{4x}{7}$

Cost of fencing $1m=$Rs. $25$

Cost of fencing the fluid $=$Rs. $3300$

Perimeter of rectangle $\times$ cost of fencing $1$cm $=$ cost of fencing the field.

$2(l+b)\times 25=3300$

$50(l+b)=3300$

$l+b=66$

$x+\frac{4x}{7}=66$

$11x=66\times 7$

$x=42$

Length $=42$m

Breadth$=24$m.