Mensuration II (Volumes and Surface Areas of a Cuboid and a Cube) Exercise 21.3

Question: 1

Find the volume of a cuboid whose

(i) length = 12 cm, breadth = 8 cm, height = 6 cm

(ii) length =1.2 m, breadth = 30 cm, height = 15 cm

(iii) length = 15 cm, breadth = 2.5 dm, height = 8 cm.

Solution:

 

Question: 2

Find the volume of a cube whose side is

(i) 4 cm

(ii) 8 cm

(iii) 1.5 dm

(iv) 1.2 m

(v) 25 mm

Solution:

 

Question: 3

Find the height of a cuboid of volume 100 cm³, whose length and breadth are 5 cm and 4 cm respectively.

Solution:

 

Question: 4

A cuboidal vessel is 10 cm long and 5 cm wide. How high it must be made to hold 300 cm³ of a liquid?

Solution:

 

Question: 5

A milk container is 8 cm long and 50 cm wide. What should be its height so that it can hold 4 litres of milk?

Solution:

 

Question: 6

A cuboidal wooden block contains 36 cm³ wood. If it be 4 cm long and 3 cm wide, find its height.

Solution:

 

Question: 7

What will happen to the volume of a cube, if its edge is

(i) halved

(ii) trebled?

Solution:

 

Question: 8

What will happen to the volume of a cuboid if its:

(i) Length is doubled, height is same and breadth is halved?

(ii) Length is doubled, height is doubled and breadth is same?

Solution:

 

Question: 9

Three cuboids of dimensions 5 cm × 6 cm × 7cm, 4cm × 7cm × 8 cm and 2 cm × 3 cm × 13 cm are melted and a cube is made. Find the side of cube.

Solution: