NCERT Class 9 Solutions: Surface Areas and Volumes (Chapter 13) Exercise 13.6 – Part 2
Q3 A soft drink is available in two packs

A tin can with a rectangular base of length and width , having a height of and

A plastic cylinder with circular base of diameter and height
Which container has greater capacity and by how much?
Solution (i)
Capacity of tin can
Capacity
Solution (ii)
Capacity or volume of plastic cylinder is given as
Diameter, therefore radius(r)
Height (h)
Therefore, capacity
Clearly the second container, the plastic cylinder has greater capacity than the first container, a tin can. The cylinder has more volume.
Q4 If the lateral surface of a cylinder is and its height is ,and then find

Radius of its base

Its volume .()
Solution:

Consider the radius of the cylinder be
Height

Later surface area




So, the radius of the base is


Now, volume of cylinder
Q5 It costs to paint the inner curved surface of a cylindrical vessel deep. If the cost of painting is at the rate of find

Inner curved surface area of the vessel

Radius of the base

Capacity of the vessel
Solution:

Inner curved surface area of the vessel


Radius of the base

Consider the radius of the base

The height of the cylindrical vessel
We know that inner curved surface area

Therefore,




So, the radius of the base is


Capacity of the vessel