Prob. $(3)$: An iron ore is reduced in a furnace in accondance with the following equation: $F{e}_2{O}_1+9CO=2Fe+3C{O}_2+6CO$

The necessary carbon monoxide is obtained by the combustion of coke at the bottom of the furnace. The coke contains $86\%.$ which $6\%$ is absorbed by the reduced iron and $80\%$ is burned to $CO,$ no $C{O}_2$ being formed in the combustion. Find:

$(1)$ The volume of $CO$ necessary to reduce one metric ton of inen.

$(2)$ The vol. of air used in burning this amount of coke:

$(3)$ The vol. and percentage composition of the gases.