Exams › SSC CGL (Prelims) › General

A cylinder of radius 5 cm and height 12 cm is bored through its full height by a cylindrical hole of radius 3 cm. What percentage of the original volume is removed?

1. 20%
2. 36%
3. 48%
4. 64%

Correct answer: 36%

Solution

Original volume = \(\pi r^2 h = \pi\cdot 5^2\cdot 12\). Removed volume = \(\pi\cdot 3^2\cdot 12\). The ratio removed/original = \(9/25\), which is 36%.

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