If the radius of the base of a right circular cylinder is reduced to one-third, keeping the height same, what is the ratio of the volume of the reduced cylinder to that of the original?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 1 : 9.
Original volume ∝ r²h
New radius = (1/3)r → New volume ∝ (1/3)² × h = (1/9) × r²h
Ratio = New volume : Original volume = 1 : 9