A rectangular brick measures 18cm by 9cm by 6 cm. Find the number of bricks required to build a rectangular wall 4.5m wide, 18cm thick and 3.6m high.
please explain with details.

First find the volume of brick = 18 * 9 * 6 = 972 cm^3

volume of wall

Take note of units in meters. 1m = 100 cm

so we have 4.5 * 100 * 18 * 3.6 * 100 = 2,916,000 cm^3

So we divide the volume of wall by volume of brick to know how many bricks required

2,916,000/972 = 3,000 bricks