A 20m deep well having diameter 7m is dug and the earth dug out is evenly spread to form a platform 22m by 14m. Find the height of the platform.
2.5 m
Let h be the height of the platform
Volume of the cylinder = πr2h=227×(3.5)2×20=770m3
Volume of a cuboid = l × b × h = 22 × 14 × h = 308h
Volume of cylinder = volume of cuboid
770 = 308h ⟹ h = 2.5 m
Height of platform = 2.5m