There is a minimum required volume of combustion air for fue…

There is a minimum required volume of combustion air for fuel fired appliances. From Figure 304.5.2 on page 3-21 in the IFGC, how much combustion air is required for a 50,000 Btu/h draft appliance plus a 50,000 Btu/h fan assisted appliance in the same room with an ACH of 0.35?