Find the number of bricks measuring 25 cm in length, 5 cm in breadth and 20 cm in height for a wall 40 m long, 80 cm broad and 6 m in height.

Correct option is C

Given:
Dimensions of one brick = 25 cm × 5 cm × 20 cm
Dimensions of wall = 40 m × 80 cm × 6 m
Formula Used:
​$$\text{Number of bricks} = \frac{\text{Volume of wall}}{\text{Volume of one brick}}$$
1 m = 100 cm
40 m = 4000 cm
6 m = 600 cm
Solution:
Wall dimensions = 4000 cm × 80 cm × 600 cm
Volume of wall = (4000 × 80 × 600) cm³
Volume of one brick = (25 × 5 × 20) cm³

Number of bricks =$$\frac{4000 × 80 × 600}{25 × 5 × 20}$$​ = 76800