Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: · Marks: · Difficulty:
A solid metallic cylinder of base radius 3 cm and height 5 cm is melted to form cones, each of height 1 cm and base radius 1 mm. The number of cones is
(a)450
(b)1350
(c)4500
(d)13500
Answer
Answer (as printed): D
Explanation
Volume of cylinder $=(\pi \times 3 \times 3 \times 5) \mathrm{cm}^{3}=45 \pi \mathrm{cm}^{3}$. Volume of 1 cone $=\left(\frac{1}{3} \pi \times \frac{1}{10} \times \frac{1}{10} \times 1\right) \mathrm{cm}^{3}=\frac{\pi}{300} \mathrm{cm}^{3}$. $$\text { ∴ Number of cones }=\left(45 \pi \times \frac{300}{\pi}\right)=13500 .$$