A cistern, internally measuring 150 cm × 120 cm × 110 cm, has 129600 cm3 of water in it. Porous bricks are placed in the water until the cistern is full to the brim. Each brick absorbs one-seventeenth of its own volume of water. How many bricks can be put in without overflowing the water, each brick being 22.5 cm × 7.5 cm × 6.5 cm?
Volume of cistern = 150 × 120 × 110
= 1980000 cm3
Volume to be filled in cistern = 1980000 − 129600
= 1850400 cm3
Let n numbers of porous bricks were placed in the cistern.
Volume of n bricks = n × 22.5 × 7.5 × 6.5
= 1096.875n
As each brick absorbs one-seventeenth of its volume, therefore,
volume absorbed by these bricks
n = 1792.41
Therefore, 1792 bricks were placed in the cistern.