Q. If the total surface area of a cylinder is equal to three times its curved surface area, then h : r is:
✅ Correct Answer: (C)
1 : 2
Explanation: 2πr(r+h) = 3(2πrh) ⇒ r + h = 3h ⇒ r = 2h ⇒ h : r = 1 : 2.
Explanation by: Mr. Dubey
2πr(r+h) = 3(2πrh) ⇒ r + h = 3h ⇒ r = 2h ⇒ h : r = 1 : 2.