Mensuration Practice Test 9

Diameter of the circular cylinder = 20 cm
Radius = r = 10 cm
Height = h = 30 cm.

Volume = $\mathit{\pi }{\mathit{r}}^2\mathit{h}$
= $\frac{22}{7}\times 10\times 10\times 30$ = $9428.57\mathit{c}{\mathit{m}}^3$
Volume of the circular cylinder upto 5 cm height.
= $\frac{22}{7}\times 10\times 5\times 10$ = 1571.42 $\mathit{c}{\mathit{m}}^3$
Volume of the remaining cylinder
= 9,428.57 − 1,571.42 = 7,857.15 $\mathit{c}{\mathit{m}}^2$
Radius of the sphere = 5 cm
Volume of the sphere = $\frac{4}{3}\times \frac{22}{7}\times 5\times 5\times 5$
= 523.80 $\mathit{c}{\mathit{m}}^3$
Metal spheres needed = $\frac{7857.15}{523.80}$ = 15