Methane Is Burned With Air In A Continuous Steady State Combustion Reactor To Yi

Methane is burned with air in a continuous steady-state combustion reactor to yield a mixture of CO2, CO and water. The reactions taking place are

CH4 + 1½O2 → CO + 2H2O

CH4 + 2O2 → CO2 + 2H2O

The feed to the reactor contains 7.8 mol % CH4, 19.4 mol % O2, and 72.8 mol % N2. The percentage conversion of methane is 90.0% and the gas leaving the reactor contains 8 mol CO2/mol CO. How do i calculate the molar composition of the product stream using: Molecular and atomic balances and extent of teactions?