Question

A rectangular ground is $90m$ long and $32m$ broad. In the middle of the ground there is a circular tank of radius $14m$. Find the cost of turfing the remaining portion at the rate of $Rs.50$ per square metre.

Answer 1

Area of the rectangular ground $=90m\times 32m=(90\times 32)m^2=2880m^2$
Given:
Radius of the circular tank $\left(r\right)=14m$
Area covered by the circular tank $=\pi r^2=\frac{22}{7}\times 14\times 14$
$=616m^2$
Remaining portion of the rectangular ground for turfing = (Area of the rectangular ground - Area covered by the circular tank)
$=(2880-616)=2264m^2$
Rate of turfing $=Rs.50$ per sq. metre
∴ Total cost of turfing the remaining ground $=Rs(50\times 2264)=Rs1,13,200$