Question

A tank 40 m long, 30 m broad, and 20 m deep is dug in a field 1000 m long and 30 m wide. By how much will the level of the field rise if the earth dug out the tank is evenly spread over the field?

Answer 1

volume of earth dug out=volume of tank
                                   =40*30*20
                                   =24000 cubic metre

 area of field not dug out= (1000-40)*30
                                   =960*30
                                   =28800 metre square

increase in leavel of the field = 24000/28800
                                          = 0.8333m