A solid cylinder of radius 6 cm is drilled by three cylindrical holes, each of radius 2 cm and length equal to the full height of the cylinder. The volume removed is approximately what percent of the original cylinder’s volume?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 33.33%.
Voriginal = πR2h
⇒ π(6)2h = 36πh
Vhole = πr2h
⇒ π(2)2h = 4πh
Total volume of 3 holes = 3 × 4πh = 12πh
Percentage removed = (12πh/36πh) × 100
⇒ 100/3 = 33.33%