(Solved): 9. In a certain region of lowa, it has been found that the original depth of topsoil around the yea ...

9. In a certain region of lowa, it has been found that the original depth of topsoil around the year 1900 was 40 cm. The total amount of loss of topsoil between the year 1900 and the year 2000 was 2859 ton/ha, and the total amount of soil formation during the same period was 143 ton/ha. If the rates of both loss and formation of soil remain unchanged, by which year is the topsoil in this region of lowa expected to become completely lost?