Question

A 21m deep well with diameter 10m is dug up and the earth from digging is spread evenly to form a platform 22m*15m . Determine the height of the platform.

Answer 1

Diameter of the well = 10 m
Radius of the well = 10/2 =5 m
Depth of the well = 21 m

Volume of the mud dug from the well = πr^2h
= 22/7 × 5 × 5 × 21
= 1650 m3

Area of the rectangular plot where the mud is spread = 22 x 15
Let the height of the plotfarm be h metres.

Volume of the plot form = Volume of the mud taken from the well
= 22 x 15 x h = 1650
h = 1650 / 22x15
h = 5 m