SSC CPO 2019 PYQ — Question 136

SSC CPO Tier I - 13th December 2019 - Shift 1 • Quantitative Aptitude • Q136

A cylinder of maximum possible size is cut from a solid wooden cube. The remaining material of the cube is what percentage of the original cube?

Show answer & explanation

Correct answer: D

Explanation

The correct answer is Option 4 i.e. 21.5

A right circular cylinder of maximum volume is cut out from a solid wooden cube

Let say cube side  = a

Volume of Cube =  a³

A right circular cylinder of maximum volume

⇒ Height = a

Diameter = a

Radius = a/2

Right circular cylinder of maximum volume  = π (a/2)² × a

= (π/4)a³    [Using π = 22/7]

= (11/14) a³

Volume left = a³ - (11/14) a³ = (3/14)a³

Hence,

Volume left  in % of original cube = 100 × (3/14)a³/ a³

= 150/7 = 21.5%