Question

A rectangular field has its length and breadth in the ratio 5 : 3 Its area is 3.75 hectares The cost of fencing it at Rs 5 per metre is

• A. $Rs400$
• B. $Rs4000$
  
• C. $Rs1000$
• D. $Rs500$

Answer 1

The correct option is B $Rs4000$

Let the length and breadth be $5x$ and $3x$

Area =$3.75$ hectares$=3.75\times 10000=37500.00sq.meter$

$\therefore 3x\times 5x=37500$

$\Rightarrow 15x^2=37500$

$\Rightarrow x^2=2500$

$\Rightarrow x=50$

$\therefore length=5\times 50=250m$

$Breadth=3\times 50=150m$

Perimeter of the field$=2(l+b)$

$\Rightarrow 2(250+150)$

$\Rightarrow 2\times 400=800m$

$\therefore$Cost of fencing$=800\times 5=Rs.4000$