Question

A rectangular plot is 80m long and 60m wide. A square tank of side 20m is dug and the earth dug out is spread evenly on the remaining portion of the plot thereby raising the level by 50cm. Find the depth of the tank.

Answer 1

let the depth of tank be h metres

volume by which remaining part of plot raises
= 20m×40m×0.50m + 60m×60m×0.50m
= 400m^3 + 1800m^3
= 2200m^3

since,the volume of earth removed is spread on the rest of the plot
therefore,
volume of tank = 2200m^3

==> 20m×20m× h = 2200m^3

==> h= 2200/400m

==> h= 5.5 m

hence ,the depth of the tank = 5.5 m

hope this helps