Question

The ratio between the length and the breadth of a rectangular park is 3 : 2. If a man cycling along the boundary of the park at the speed of 12 km/hr completes one round in 8 minutes, then the area of the park (in sq. m) is:

• A. 15360
• B. 153600
• C. 30720
• D. 307200

Answer 1

The correct option is B 153600

Perimeter = Distance travelled in 8 minutes,
$\Rightarrow perimeter=\frac{12000}{60}\times 8=1600m.\left[becauseDis\tan ce=Speed\times Time\right]$
As per question length is 3x and width is $2x$
We know perimeter of rectangle is $2(L+B)$
So$,2(3x+2x)=1600$
$=>x=160$
So Length $=160\times 3=480m$
and Width $=160\times 2=320m$
Finally$,$ $Area=length\times breadth$

$=480\times 320=153600$

Hence,

option $\left(B\right)$ is correct answer.