Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: · Marks: · Difficulty:
The radii of two cones are in the ratio 2 : 1, their volumes are equal. Find the ratio of their heights.
(a)1 : 8
(b)1 : 4
(c)2 : 1
(d)4 : 1
Answer
Answer (as printed): B
Explanation
Let their radii be 2x, x and their heights be $h$ and $H$ respectively. Then, $$\frac{1}{3} \times \pi \times(2 x)^{2} \times h=\frac{1}{3} \times \pi \times x^{2} \times H \text { or } \frac{h}{H}=\frac{1}{4} .$$
Explanation as extracted from the printed page; notation may be imperfect.