Question

A solid right cylinder of iron of diameter $3cm$ and height $10cm$ is melted and formed into solid spherical balls each of diameter $1.5cm$. Find the number of balls formed.

Answer 1

Volume of solid right cylinder
$=\pi {\left(\frac{3}{2}\right)}^2\times 10$
Volume of spherical ball $=\frac{4}{3}\pi {\left(\frac{3}{4}\right)}^3$
$\therefore$ Number of balls $=\pi {\left(\frac{3}{2}\right)}^2\times 10÷\frac{4}{3}\pi {\left(\frac{3}{4}\right)}^3=40$