A 20 m deep well with diameter 7 m is dug and the earth from digging is evenly spread out to form a platform 22 m by 14 m. Find the height of the platform
As per the question,
The shape of the well will be cylindrical
Depth (h) of well = 20 m
Radius (r) of circular end of well =
Area of platform = Length × Breadth = 22 × 14 m2
Let height of the platform = H
Volume of soil dug from the well would be equal to the volume of soil that is scattered on the platform.
Volume of soil from well = Volume of soil used to make such platform
πr2h = Area * Height
π * (
)2 * 20 = 22 * 14 * H
H = 
* 
* 
= 2.5 m
Hence, the height of the platform = 2.5m
3