A well, whose diameter is 7m, has been dug 22.5 m deep and the earth dugout is used to form an embankment around it. If the height of the embankment is 1.5 m, find the width of the embankment.

Explanation

Volume of embankment=Volume of well

`pi(R^2*1.5-pir^2(1.5)=pir^22.5`

`R^2-r^2=15r^2`

`R^2=16r^2`

`R=sqrt(16r^2)=4r=4*7/2=14m`

`R=14m`

`r+x=14cm`

`x(width)=14-7/2=21/2m`.