A field is 70 m long and 40 m broad. In one corner of the field, a pit which is 10 m long, 8 m broad and 5 m deep, has been dug out. The earth taken out of it is evenly spread over the remaining part of the field. Find the rise in the level of the field.

Explanation

Area of the field `= (70 xx 40) m^(2) = 2800 m^(2)`
Area of the pit `= (10 xx 8) m^(2) = 80 m^(2)`
Area over which the earth is spread over
`= (2800 - 80) m^(2) = 2720 m^(2)`

Volume of the earth dug out `= (10 xx 8 xx 5) m^(3) = 400 m^(3)`
Rise in level of the field `= (("volume of the earth dug out")/("area on which the earth is spread"))`
`= ((400)/(2720))m = ((400 xx 100)/(2720)) cm`
`= (250)/(17) cm = 14.70 cm`