A solid toy is in the form of a hemisphere surmounted by a right circular cone. The height of the cone is 2 cm and diameter of the base is 4 cm. If a right circular cylinder circumscribes the toy, find how much more space it will cover?
Given: Radius of cone = radius of cylinder = radius of hemisphere = 
= 2 cm
Height of cone = 2 cm
To find: Volume of cylinder after toy is inserted.
Formula used:
Volume of cylinder = πr2h
Volume of cone = 
Volume of hemisphere = 
Explanation:
Volume of cone = 
Volume of hemisphere = 
Volume of toy = Volume of cone + Volume of hemisphere
= 8π
Now the height of cylinder = height of cone + height of hemisphere
As height of hemisphere = radius of hemisphere
⇒ Height of hemisphere = 2 cm
⇒ height of cylinder = 2 cm + 2 cm = 4 cm
Volume of cylinder = πr2h
= π(2)2(4)
= 16π cm3
Volume of cylinder after toy is inserted = Volume of cylinder – volume of toy
= 16π – 8π
= 8π cm3
Hence the remaining volume is 8π cm3.