Question

 A well of diameter 4m is dug 21m deep. The earth taken out of it has been spread evenly all around it in the shape of a circular ring of width 3m to form an embankment. Find the height of the embankment.​

Answer 1

ANSWER: 4 m

EXPLANATION:

Given, Diameter =4 m

Radius =2 m    h=21 m

V=πr²h  

=π(2)(2)(21)

=84π

Volume of soil dug from well = volume of earth used to form embankment

⇒84π=π(5² − 2²)h

h=    84/25−4

=84/21

= 4 m

i hope it helps....