RS Aggarwal Class 8 Maths Solutions Chapter 20 - Volume and Surface Area of Solids

Find the volume, lateral surface area and the total surface area of the cuboid whose dimensions are:

(i) length = 22 cm, breadth = 12 cm and height = 7.5 cm

(ii) length = 15 m, breadth = 6 m and height = 9 dm

(iii) length = 24 m, breadth = 25 cm and height = 6 m

(iv) length = 48 cm, breadth = 6 dm and height = 1 m

The dimensions of a rectangular water tank are 2 m 75 cm by 1 m 80 cm by 1 m 40 cm. How many litres of water does it hold when filled to the brim?

A solid rectangular piece of iron measures 1.05 m x 70 cm x 1.5 cm. Find the weight of this piece in kilograms if 1 cm³ of iron weighs 8 grams.

The area of a courtyard is 3750 m². Find the cost of covering it with gravel to a height of 1 cm if the gravel costs Rs. 6.40 per cubic metre.

How many persons can be accommodated in a hall of length 16 m, breadth 12.5 m and height 4.5 m, assuming that 3.6 m³ of air is required for each person?

A cardboard box is 1.2 m long, 72 cm wide and 54 cm high. How many bars of soap can be put into it if each bar measures 6 cm x 4.5 cm x 4 cm?

The size of a matchbox is 4 cm x 2.5 cm x 1.5 cm. What is the volume of a packet containing 144 matchboxes? How many such packets can be placed in a carton of size 1.5 m x 84 cm x 60 cm?

How many planks of size 2 m x 25 cm x 8 cm can be prepared from a wooden block 5 m long, 70 cm broad and 32 cm thick, assuming that there is no wastage?

How many bricks, each of size 25 cm x 13.5 cm x 6 cm, will be required to build a wall 8 m long, 5.4 m high and 33 cm thick?

A wall 15 m long, 30 cm wide and 4 m high is made of bricks, each measuring 22 cm x 12.5 cm x 7.5 cm. If of the total volume of the wall consists of mortar, how many 12bricks are there in the wall?

Hint. Volume of bricks in the wall = {(1500 x 30 x 400) x (1500 x 30 x 400)1 cm³.