$13\mathrm{.}17$ Methane $($CH$4)$ enters a furnace and burns completely with $150\%$ of theoretical air

entering at $25$C$,0\mathrm{.}945$ bar, $75\%$ relative humidity. Determine

a$.$ the balanced reaction equation. $(1,3,0\mathrm{.}367,1,2\mathrm{.}367,1,11\mathrm{.}28)$

b$.$ the dew point temperature of the combustion products, in $$C$,$ when cooled at