You cannot copy content of this page

NCERT solution class 8 chapter 11 Mensuration

Exercise 11.1   Exercise 11.2   Exercise 11.3   Exercise 11.4

Exercise 11.4

Question 1

Given a cylindrical tank, in which situation will you find surface area and in which situation volume.

(a) To find how much it can hold

(b) Number of cement bags required to plaster it

(c) To find the number of smaller tanks that can be filled with water from it.

Sol :

(a) In this situation, we will find the volume.

(b) In this situation, we will find the surface area.

(c) In this situation, we will find the volume.



Question 2

Diameter of cylinder A is 7 cm, and the height is 14 cm. Diameter of cylinder B is 14 cm and height is 7 cm. Without doing any calculations can you suggest whose volume is greater? Verify it by finding the volume of both the cylinders. Check whether the cylinder with greater volume also has greater surface area?

Sol :

The heights and diameters of these cylinders A and B are interchanged.

We know that,

Volume of cylinder

If measures of r and h are same, then the cylinder with greater radius will have greater area.

Radius of cylinder A = cm

Radius of cylinder B = cm = 7 cm

As the radius of cylinder B is greater, therefore, the volume of cylinder B will be greater.

Let us verify it by calculating the volume of both the cylinders.

Volume of cylinder A

Volume of cylinder B

Volume of cylinder B is greater.

Surface area of cylinder A

Surface area of cylinder B

Thus, the surface area of cylinder B is also greater than the surface area of cylinder A.



Question 3

Find the height of a cuboid whose base area is 180 cm2 and volume is 900 cm3?

Sol :

Base area of the cuboid = Length × Breadth = 180 cm2

Volume of cuboid = Length × Breadth × Height

900 cm3 = 180 cm2 × Height

Thus, the height of the cuboid is 5 cm.


Question 4

A cuboid is of dimensions 60 cm × 54 cm × 30 cm. How many small cubes with side 6 cm can be placed in the given cuboid?

Sol :

Volume of cuboid = 60 cm × 54 cm × 30 cm = 97200 cm3

Side of the cube = 6 cm

Volume of the cube = (6)3 cm3 = 216 cm3

Required number of cubes =

Thus, 450 cubes can be placed in the given cuboid.



Question 5

Find the height of the cylinder whose volume is 1.54 m3 and diameter of the base is 140 cm?

Sol :

Diameter of the base = 140 cm

Radius (r) of the base

Volume of cylinder

Thus, the height of the cylinder is 1 m.



Question 6

A milk tank is in the form of cylinder whose radius is 1.5 m and length is 7 m. Find the quantity of milk in litres that can be stored in the tank?

Sol :

Length of cylinder = 7 m

Volume of cylinder

1m3 = 1000 L

Required quantity = (49.5 × 1000) L = 49500 L

Therefore, 49500 L of milk can be stored in the tank.


Question 7

If each edge of a cube is doubled,

(i) how many times will its surface area increase?

(ii) how many times will its volume increase?

Sol :

(i) Let initially the edge of the cube be l.

Initial surface area = 6l2

If each edge of the cube is doubled, then it becomes 2l.

New surface area = 6(2l)2 = 24l2 = 4 × 6l2

Clearly, the surface area will be increased by 4 times.

(ii) Initial volume of the cube = l3

When each edge of the cube is doubled, it becomes 2l.

New volume = (2l)3 = 8l3 = 8 × l3

Clearly, the volume of the cube will be increased by 8 times.



Question 8

Water is pouring into a cubiodal reservoir at the rate of 60 litres per minute. If the volume of reservoir is 108 m3, find the number of hours it will take to fill the reservoir.

Sol :

Volume of cuboidal reservoir = 108 m3 = (108 × 1000) L = 108000 L

It is given that water is being poured at the rate of 60 L per minute.

That is, (60 × 60) L = 3600 L per hour

Required number of hours = 30 hours

Thus, it will take 30 hours to fill the reservoir.

4 thoughts on “NCERT solution class 8 chapter 11 Mensuration”

  1. I am the head web developer for the E-mail Extractor and Online Search Engine Scraper by Creative Bear Tech – Basically, this internet search engine scraper can scrape the majority of the search engines, including Google, Bing, AOL, Yandex along with social media networks including Facebook, Instagram, Twitter, LinkedIn, Yellow Pages, Google Maps and so much more. I find that it will be much easier if you browse through the complete manual at The software program is not official yet, but immediately after it is, it will be accessible on We are currently beta testing the software and looking for beta tester and software reviewers. You will be given the full licence key for the computer software and can even scrape B2B contact details for your own niche. If interested, please give me a shout on Facebook just reply to this thread.

Leave a Comment

Your email address will not be published. Required fields are marked *

error: Content is protected !!
Free Web Hosting