Question:
A right cylindrical vessel is full of water. How many right cones having the same radius and height as those of the right cylinder will be needed to store that water?
Solution:
Let the radius and height of the cone be $r$ and $h$, respectively. Then,
Radius of the cylindrical vessel $=r$ and
Height of the cylindrical vessel $=h$
Now,
The number of cones $=\frac{\text { Volume of the cylindrical vessel }}{\text { Volume of a cone }}$
$=\frac{\pi r^{2} h}{\left(\frac{1}{3} \pi r^{2} h\right)}$
$=3$
So, the number of cones that will be needed to store the water is 3.