A 20m deep well with diameter 7m is dug and the earth from digging is evenly spread out to form a platform 22m by14m.Find the heinght of the platform.

the well will be in the cylindrical shape. its radius r =7/2m

and height h =20 m.

the volume of the earth dug out =

area of the platform= 22*14 m square

let the height of the platform be H m.

volume of the platform = volume of the earth dug out

22*14*H=22*35

H=35/14=5/2=2.5 m.

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