Question
How many bricks each of dimensions 25cm x16cm x 10 cm will be needed to build a wall 24 m long, 6m high and 0.4 m thick?
- 1440
- 14400
- 4400
- none of these
Hint:
We are given the dimensions of brick and wall. We have to find the number of bricks needed to make the wall. We can see that the dimensions are different. So, it is a cuboid. We have to use the formula of volume of cuboid to find the answer.
The correct answer is: 1440
Let the length, breadth and height of the brick be denoted by A, B, and C respectively.
A = 25cm
B = 16cm
C = 10cm
Let the length, breadth and height of the wall be denoted as l, b and h respectively.
l = 24m
b = 0.4m
h = 6m
Let the number of bricks required to make the wall be “N”.
Now, we will find the volume of bricks and the wall. Both are cuboids so we will use the formula for volume of cuboids.
Volume = length × breadth × height
Volume of brick = A × B × C
= 25 × 16 × 10
= 4000 cu. cm
Volume of wall = l × b × h
= 24 × 0.4 × 6
= 57.6 cu. m
We will need to convert the volume of wall into cubic centimeters.
1 m = 100 cm
1 cu. m = 106 cm
So, the volume of wall = 57.6 × 106 cu. cm
Now, N number of bricks make the wall. So, we can write
Volume of wall = N × Volume of bricks
Rearranging we get,
N × Volume of bricks = Volume of wall
Dividing both the sides by Volume of bricks
So, the number of bricks is 14400.
For such questions, we should know the formulas of volumes for different shapes.
Related Questions to study
Find the area of shaded region in adjoining figure.
Find the area of shaded region in adjoining figure.
Find the area of Rhombus whose perimeter is 48cm and altitude is 8 5 cm
For such questions, we should know area and perimeter of different shapes. We should know properties of different shape.
Find the area of Rhombus whose perimeter is 48cm and altitude is 8 5 cm
For such questions, we should know area and perimeter of different shapes. We should know properties of different shape.
The length of side of an equilateral triangular garden whose perimeter is 66cm is
For such questions, we should know the properties of equilateral triangle.
The length of side of an equilateral triangular garden whose perimeter is 66cm is
For such questions, we should know the properties of equilateral triangle.
From subtract
For such questions, we should know the concept of like and unlike terms.
From subtract
For such questions, we should know the concept of like and unlike terms.
If
For such questions, we should know rules of indices.
If
For such questions, we should know rules of indices.