Warm Up $02)$

The product gas from a solid fuel combustion reaction has the following dry$-$basis molar composition: $72\mathrm{.}0\%C{O}_2,2\mathrm{.}57\%CO,0\mathrm{.}0592\%S{O}_2,$ and $25\mathrm{.}4\%O_2.$ Pure oxygen is fed to the furnace in $20\%$ excess of that required to burn the fuel completely. There is no oxygen in the fuel. Calculate the elemental composition $($mole $\%$ of the various elements$)$ of the fuel, stating any assumptions you have to make to arrive at your answer.