3. 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.
According to the question, the volume of soil dug will be equal to the volume of the platform created.
Thus we can write :
The volume of soil dug = Volume of platform
Thus the height of the platform created is 2.5 m.