I think the reaction involved here would be a combustion reaction since one of the products mentioned above is carbon dioxide. A combustion reaction involves the reaction of a hydrocarbon with oxygen producing carbon dioxide and water. The combustion of methane is expressed as:
CH4 + 2O2 = CO2 + 2H2O
Given moles of CH4, we calculate the amount of CO2 produced using the relation of the substnaces in the reaction. We do as follows:
X mol CH4 ( 1 mol CO2 / 1 mol CH4 ) = X mol CO2
You simply substitute the number of moles of methane to the equation and evaluate it to get the moles of CO2 produced.