Question

A wall 15 m long, 30 cm wide and 4 m high is made of bricks, each measuring

22 cm x 12.5 cm x 7.5 cm . If 1/12 of the total volume of the wall consists of mortar, how many
12
bricks are there in the wall​

Answer 1

l = 15m = 1500cm
b= 30cm
h= 4m= 400cm



So, total volume of the wall= l×b×h
= 1500×30×400= 1,80,00,000 cm^3


Now, volume of one brick= 22×12.5×7.5= 2062.5 cm^3


Volume of wall containing only bricks= total volume of the wall - volume of wall containing mortar
= 1,80,00,000 - (1,80,00,000 × 1/12)
= 1,65,00,000 cm^3


So, no. of bricks = volume of wall containing bricks ÷ volume of one brick
= 1,65,00,000 ÷ 2062.5
= 8000 bricks.