The radius of a cylinder is doubled due to which the volume of the new cylinder also gets doubled. The height of the new cylinder is what percentage of the old cylinder?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 50%.
Let original radius = r, height = h
Volume of cylinder = πr2h
New radius = 2r
New volume = 2 × original = 2πr2h
New height = H
New volume = π(2r)2 × H = π × 4r2 × H
Now,
⇒ π × 4r2 × H = 2πr2h
⇒ 4H = 2h
⇒ H = 2h/4 = h/2
So, the new height is 50% of the old height