The radius of the base of a right circular cylinder is intersected by 20%. By what % should height be reduced so that its volume remains the same as before?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 
.
R = r + r/5 = 6r/5
πr²h =π R² H
πr²h = π (6r/5)² H
r²h= (36r²/25) H
H/h = 25/36
% height reduced = (11/36) 100 = %