Question

The radius of a cylinder is increased by 120% and its height is decreased by 40%. What is the percentage increase in its volume?​

Answer 1

Answer:

Explanation:

If the radius of a cylinder is increased by 20% and its height is decreased by 10%.

Solution :

Let r be the radius of cylinder is increased by 20%

i.e,  

The old radius is 5 and new radius is 6.

Let h be the height of cylinder is increased by 10%

i.e,  

The old height is 10 and new height is 11.

The volume of old cylinder with r=5 and h=10

 The volume of new cylinder with r=6 and h=11

Volume change is

Percentage change is

Therefore, The percentage change in the volume is 6.4%.