The paint in a certain container is sufficient to paint an area equal to 9.375 m2. How many bricks of dimensions 22.5 cm × 10 cm × 7.5 cm can be painted out of this container?
Solution:
Given: Dimensions of the brick 22.5cm × 10cm × 7.5cm
Since brick is cuboidal in shape, the surface area of the brick will be the total surface area of the cuboid.
Hence, the area of each brick to be painted will be the total surface area of the cuboid
Total surface area of cuboid = 2(lb + bh + hl)
The number of bricks that can be painted out of the container can be calculated by dividing the area which can be painted with paint available in the container by the area of each brick.
The area which can be painted with the paint available in the container = 9.375m2.
Let the length, breadth, and height of the bricks be l, b, and h respectively.
l = 22.5 cm
b = 10 cm
h = 7.5 cm
The area of each brick to be painted = 2(lb + bh + hl)
2(lb + bh + hl) = 2 × (22.5 cm × 10 cm + 10 cm × 7.5 cm + 7.5 cm × 22.5 cm)
= 2 × (225 cm2 + 75 cm2 + 168.75 cm2)
= 2 × 468.75 cm2
= 937.5 cm2
Number of bricks that can be painted = The area which can be painted with the paint available in the container / The area of each brick
= 9.375 m2 / 937.5 cm2
= (9.375 × 10000 cm2) / 937.5 cm2 [since 1m2 = 10000cm2]
= 100
Thus, the number of bricks that can be painted out of the container is 100.
☛ Check: NCERT Solutions for Class 9 Maths Chapter 13
Video Solution:
The paint in a certain container is sufficient to paint an area equal to 9.375 m². How many bricks of dimensions 22.5 cm × 10 cm × 7.5 cm can be painted out of this container?
Class 9 Maths NCERT Solutions Chapter 13 Exercise 13.1 Question 4
Summary:
It is given that the paint in a certain container is sufficient to paint an area equal to 9.375 m2. We have found that the number of bricks that can be painted out of the container is 100.
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