A30l digester bioreactor is charged with media and 3.75l of cow dung. the reactor produces 5l of biogas per one liter of cow dung at a pressure of 1 atm and a temperature of 27oc. the biogas leaving the digester is saturated with water. on a dry basis, this gas contains 80 mol% methane and 20 mol% carbon dioxide. the gas is then fed to a furnace with 7 mols of dry air and undergoes complete combustion and complete conversion. determine the composition of the resulting gas.