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# 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. - CBSE Class 10 - Mathematics

ConceptSurface Areas and Volumes Examples and Solutions

#### Question

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?

#### Solution

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/17(1096.875)

1850400 + n/17 (1096.875) = (1096.875)n

1850400 = (16n)/17(1096.875)

n = 1792.41

Therefore, 1792 bricks were placed in the cistern.

Is there an error in this question or solution?

#### APPEARS IN

NCERT Solution for Mathematics Textbook for Class 10 (2019 to Current)
Chapter 13: Surface Areas and Volumes
Ex. 13.40 | Q: 3 | Page no. 258

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Solution 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. Concept: Surface Areas and Volumes Examples and Solutions.
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