Question

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Answer 1

Shaded part refers to embankment
Amount of mud for making embankment=Amount of mud taken out by well
Note Volume remains constant
Well is of cylindrical shape
Volume =πr^2h
=π*7*7*14
=686π
now Embankment doesn't cover the part of well (refer figure)
it's just the outer covering
The embankment is also of cylindrical shape
Volume of outer cylinder(red)-Volume of inner cylinder (green)=πh(r2²-r1²)
=πh(12^2-7^2)
=πh95
Now equate both equations
we get h=686/95
h=7.22
Hope it helps
Pls do mention if it's incorrect
:)