A field is 200m long and 150m broad. There is a plot, 50m long and 40m broad, near the field. The plot is dug 7m deep and the earth taken out is spread evenly on the field. By how many metres is the level of the field raised? Give the  answer to the second place of decimal.

Explanation

Volume of the earth dugout = `50xx40xx7 m^3`

Suppose level of the Earth dugout rises by h m.

`therefore` Volume of the field (cuboidal) = Volume of the Earth dugout

`200xx50xxh = 50xx40xx7`

`h=50xx40xx7/200xx50xxh`

`h = 0.47 m`

Hence, height is 0.47m.