The volume of a hemisphere is numerically equal to four times its curved surface area. Find its radius.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 12 units.
Volume = (2/3)πr3
Curved surface area = 2πr2
(2/3)πr2 = 4 × 2πr2 = 8πr2
⇒ (2/3)r = 8
⇒ r = 12