Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: 2007 · Marks: · Difficulty:
The radius of the base and height of a metallic solid cylinder are $r$ cm and 6 cm respectively. It is melted and recast into a solid cone of the same radius of base. The height of the cone is
(a)9 cm
(b)18 cm
(c)27 cm
(d)54 cm
Answer
Answer (as printed): B
Explanation
Let the height of the cone be $h \mathrm{cm}$. Then, $\pi \times r^{2} \times 6=\frac{1}{3} \times \pi \times r^{2} \times h \Rightarrow h=18 \mathrm{cm}$.