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?


According to the question:

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 = (1096.875)


1850400 + (1096.875) = (1096.875)n


1850400 = (1096.875)


n = 1792.41


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