Question

A lane 180 m long and 5 m wide is to be paved with bricks of length 20 cm and breadth 15 cm. Find the cost of bricks that are required, at the rate of Rs 750 per thousand.

Answer 1

We have,
Length of the lane = 180 m
Breadth of the lane = 5 m
Area of a lane = Length x Breadth = 180 m x 5 m = 900 m²
Length of the brick = 20 cm
Breadth of the brick = 15 cm
Area of a brick = Length x Breadth = 20 cm x 15 cm = 300 cm² = 0.03 m² [Since 1 m² = 10000 cm² ]

Required number of bricks = $\frac{900{\mathrm{m}}^2}{0.03{\mathrm{m}}^2}=30000$

Cost of 1000 bricks = Rs. 750

∴ Total cost of 30,000 bricks = Rs. $\left(\frac{750\times 30,000}{1000}\right)=\mathrm{Rs}.22,500$