Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: 2005 · Marks: · Difficulty:
If the radius of the base of a right circular cylinder is halved, keeping the height same, what is the ratio of the volume of the reduced cylinder to that of the original one?
(a)1 : 2
(b)1 : 4
(c)1 : 8
(d)8 : 1
Answer
Answer (as printed): B
Explanation
Let original radius $=R$. Then, new radius $=\frac{R}{2}$. $$\frac{\text { Volume of reduced cylinder }}{\text { Volume of original cylinder }}=\frac{\pi \times\left(\frac{R}{2}\right)^{2} \times h}{\pi \times R^{2} \times h}=\frac{1}{4} .$$
Explanation as extracted from the printed page; notation may be imperfect.