If ratio between volume of a cylinder and volume of sphere is 3 : 1, then find the ratio between total surface area of cylinder to total surface area of sphere, radius of sphere is equal to radius of cylinder?
Correct Answer :
5 : 2
Solution :
The correct option is 5 : 2.
Let the radius of the sphere be and the radius of the cylinder also be , since they are given to be equal. Let the height of the cylinder be .
First, we express the volume of the cylinder () and the volume of the sphere ():
We are given that the ratio of the volume of the cylinder to the volume of the sphere is 3 : 1.
Substitute the formulas for volume into the ratio:
Simplify the equation by canceling and :
Dividing both sides by 3, we get:
Now, we find the ratio between the total surface area of the cylinder () and the total surface area of the sphere ().
The formula for the total surface area of a cylinder is:
Substitute into the cylinder's surface area equation:
The total surface area of the sphere is:
Now, find the ratio of their total surface areas:
Cancel from the numerator and the denominator:
Therefore, the ratio of the total surface area of the cylinder to the total surface area of the sphere is 5 : 2.
Access expert-curated educational resources and study materials—completely free.
Create, conduct, and manage professional online assessments with Mindyard. Perfect for teachers and institutes.
Copyright © 2026 Mindyard. All Rights Reserved.