Question

A bucket has top and bottom diameters of $40cm$ and $20cm$ respectively. Find the volume of the bucket if its depth is $12cm$. Also, find the cost of tin sheet used for making the bucket at the rate of Rs. $120$ per ${cm}^2$

Answer 1

Volume of bucket $=\frac{1}{3}\pi$ Height $(R_{top}^2+R_{top}{R}_{bottom}+R_{bottom}^2)$
$=\frac{1}{3}\pi \times 12({20}^2+20\times 10+{10}^2)=8800c{m}^3$

Slant height, $l=\sqrt{(20-10{)}^2+{12}^2}$
$=15.62cm$

T.S.A $=\pi (R_{top}+R_{bottom})l+\pi (R_{top}^2+R_{bottom}^2)=3044.171c{m}^2$

$Cost=120\times 30.44171=Rs.3653$