A right circular cylinder of maximum volume is cut out from a solid wooden cube. The material left is what percent of the volume (nearest to an integer) of the original cube ?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 ie 21.
Radius = a/2
Height = a
Volume of cylinder = π r2h
= π × (a²/4) × a
= π × (a3/4)
= 0.21a3
Hence, 0.21 = 21