Question

How many bricks, each measuring 15cm × 10cm × 5cm, will be needed to build a wall of length 6m, width = 18cm and height = 3.5m ?

Answer 1

Hint: Now we know that the volume of cuboid can be given by length × breadth × height. Hence with the help of this formula we can calculate the volume of the wall as well as the volume of brick. Now the number of bricks required to make the wall is \[\dfrac{\text{volume of wall}}{\text{Volume of bricks}}\] .

Complete step by step answer:
Now we are given that the dimension of brick is 15cm × 10cm × 5cm.
Hence we have the length of brick is 15cm, breadth of brick is 10cm and height of bricks is 5cm.
Now we know that the volume of cuboid is given by length × breadth × height.
Hence we have the volume of brick = 15 × 10 × 5 = 750
Hence we have the volume of brick is 750 sqcm. ………………….. (1)
Now let us consider the wall.
We are given that the length of wall is 6m, breadth of wall is 18cm and the height of wall is 3.5m.
Now we know that 1m = 100cm. Hence we get,
We are given that the length of wall is 600cm, breadth of wall is 18cm and the height of wall is 350cm.
Now again the volume of cuboid is given by 600 × 18 × 350 = 3780000.
Hence the volume of wall is 3780000 sqcm. …………………….. (2)
Now the number of bricks required to build the wall is \[\dfrac{\text{volume of wall}}{\text{Volume of bricks}}\]
Hence from equation (1) and equation (2) we get,
Number of bricks is $\dfrac{3780000}{750}=5040$ .

Hence a total of 5040 bricks are required to build this wall.

Note: Now note that all the dimensions of the brick were given in centimeters and hence we could calculate the volume in sqcm but for the wall the length and height were given in meter while the width was given in centimeters. Hence we first need to convert the dimensions in centimeters. Note that while multiplying the units must be the same and when dividing the two volumes, also the units must be the same.