1 kmol of ethane (C2H6) is burned with air. It is given that the flue gas, on a dry basis, contains 7.5 mol% carbon dioxide (CO2). Assume that carbon monoxide (CO) is not formed, and that it is excess air. Assume that the composition of the air is 21 mol% oxygen (O2) and 79 mol% nitrogen (N2). Calculate the ratio, on a mass basis, between air and fuel, (A/F) mass.