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A school provides milk to the students daily in a cylindrical glasses of diameter 7 cm. If the glass is filled with milk upto an height of 12 cm, find how many litres of milk is needed to serve 1600 students.

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#### Solution

**Given:** Diameter of cylinder glass = 7 cm

Glass is filled with milk upto an height of 12 cm.

Radius of cylinder glass = `"Diameter"/2 = 7/2` = 3.5 cm

Volume of cylinder glass (V) = `pir^2h`

= `22/7 xx (3.5)^2 xx 12`

= `22/7 xx 12.25 xx 12`

= `22 xx 1.75 xx 12`

= 462 cm^{2}

Quantity of milk needed for 1600 students = `(462 xx 1600)` cm^{3}

= 739200 cm^{3}

= 739.2 litres

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