Question

Daniel is painting the walls and ceiling of a
cuboidal hall with length, breadth and height
of 15 m, 10 m and 7 m respectively. From
each can of paint 100 m² of area is painted.
How many cans of paint will she need to paint
the room?​

Answer 1

Answer:

Mensuration:

Mensuration is the branch of mathematics which concerns itself with the measurement of Lengths, areas & volume of different geometrical shapes or figures.

Surface area:

The surface area of a solid is the sum of the areas of the plane and curved faces of the solid.

It is measured in square units such as square centimetre (cm²) and square metre (m²).

Surface area of cuboid is the sum of the surface areas of its six rectangular faces.

Surface Area of Cuboid is =

2(lb + lh + bh)

By surface area of a cuboid we mean the total surface area.

The sum of the areas of 4 vertical faces of a cuboid is called its lateral surface area.

The lateral surface area or the area of the four walls of the cuboid .

Area of the four walls = 2 (l +b) h

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Solution:

Given;

Length of wall (l)= 15 m, Breadth of wall (b)= 10 m Height of wall (h) = 7 m

Total area to be painted= area of 4 walls + area of ceiling

= 2(l+b)h + lb

= 2(15+10)7 + 15×10

= 2×25×7+ 150

=50× 7+150= 350+ 150=500

Total area to be painted=500m²

Given 100m² area can be painted from each can.

Number of cans Required=

Area of hall/ area of 1 can

= 500/100= 5

Hence, 5 cans are required to paint the room.

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Hope this will help you...