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: Option D

Solution(By Examveda Team)

$$\eqalign{ & 3 \times 2\pi {r^2} = 2 \times 2\pi rh \cr & \Rightarrow 6r = 4h \cr & \Rightarrow r = \frac{2}{3}h \cr & \Rightarrow r = \left( {\frac{2}{3} \times 6} \right)m \cr & \Rightarrow r = 4\,m \cr} $$