Question : What is the radius of a normal cylinder whose height is 21 cm and curved surface area is 1386 cm2?
Option 1: 10.5 cm
Option 2: 3.5 cm
Option 3: 7 cm
Option 4: 10 cm
Correct Answer: 10.5 cm
Solution :
Given: Height(
Let the radius be
Curved surface area = 1386 cm
2
⇒
⇒
⇒
⇒
Hence, the correct answer is 10.5 cm.