The height of a right circular cylinder is 6 m. If three times the sum of the areas of its two circular faces… · ABC26GN4903
Subject: General Aptitude · Chapter: Volume and Surface Area
The height of a right circular cylinder is 6 m . If three times the sum of the areas of its two circular faces is twice the area of the curved surface, then the radius of its base is
(a)1 m
(b)2 m
(c)3 m
(d)4 m
Answer
Answer (as printed): D
Explanation
$3 \times 2 \pi r^{2}=2 \times 2 \pi r h \Rightarrow 6 r=4 h \Rightarrow r=\frac{2}{3} h=\left(\frac{2}{3} \times 6\right) \mathrm{m}=4 \mathrm{m}$.