Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: · Marks: · Difficulty:
A solid metallic cone is melted and recast into a sphere. What is the radius of the sphere? I. The radius of the base of the cone is 2.1 cm. II. The height of the cone is four times the radius of its base. III. The height of the cone is 8.4 cm.
(a)Only I and II
(b)Only II and III
(c)Only I and III
(d)Any two of the three
(e)All I, II and III
Answer
Answer (as printed): D
Explanation
$\frac{4}{3} \pi R^{3}=\frac{1}{3} \pi r^{2} h$. Now $r$ and $h$ can be determined from any two of I, II and III. Thus, R can be calculated. $\therefore$ Correct answer is (d).
Explanation as extracted from the printed page; notation may be imperfect.