Cylinder
Radius of the base of a cylinder=10 cm
Height = 20 cm
Cone
radius of the cone base= 5 cm
height = 10 cm
cone is used to fill the cylinder with water. Let n be the number of times the water in the cone is transferred in the cylinder to fill it completely.
A.T.Q
n × volume of cone = volume of cylinder

Cancelling (π) from both sides,we get
⇒n×1/3×5×5×10=10×10×20
⇒n=[2000×3]÷250
n=24
24 cones having radius 5 cm and height 10 cm will fill the cylinder having radius of the base 10 centimeters, and height 20 centimeters.