You are consulted by the room resident (25 m^3) to find an engineering solution to their breathing discomfort in the room. Suggest the minimum ventilation rate "A", to maintain CO2 levels under 1000 ppm in the room. The resident emits CO2 at a rate of 35 g/h in addition to the 48 g/h emitted by a heater. Assume that ventilation does not affect coal consumption or its CO2 emission rate. The ambient CO2 concentration is 400 ppm(0.72 g/m^3). Report to one decimal place.