Question

Find the cost of the polishing a circular table top of diameter 4 m, if the rate of polishing it is Rs. 25 per metre square. $[\text{use}\pi =3.14]$

Answer 1

Given that the diameter of the circular table top is $4m$.

To find out: Cost of polishing the top of the table at $Rs.25per{m}^2$.

Radius of the table $\left(r\right)=\frac{d}{2}$

$=\frac{4}{2}=2m$.

We know that, area of a circle $=\pi r^2$

$\therefore$ area of the table top $=3.14\times 2\times 2[\because \pi =3.14]$

$\therefore$ Area $=12.56m^2$

Now, cost of polishing $1m^2$ area $=Rs.25$.

$\therefore$ Cost of polishing $12.56m^2$ area will be:

$12.56\times 25=Rs.314$

Hence, the cost of polishing the circular table top of diameter $4m$ is $Rs.314$.