A water tank is a cylinder with radius and height in the ratio 1:3. If the radius is increased by 20%, what is the percentage increase in volume?
Show answer & explanation
Correct answer: B
Explanation
r : h = 1 : 3
Increase in radius = 20%
Volume = πr²h
New radius = 1.2r
New volume = π(1.2r)² × h
= 1.44 × (πr²h)
⇒ Increase = 1.44 − 1 = 0.44
⇒ Percentage increase = 44%