A room for smokers in an airport is 10 ft tall, 8 ft wide, and 12 ft long. There is an average of 12 people in the room at any given time over the course of a day, and each of them smoke four cigarettes per hour, on average. Each cigarette produces 1.4 mg of formaldehyde gas, and this is converted to CO2 through a 1st-order reaction, with a rate reaction of 0.008 min-1. Clean air is blown into the enclosure at 750 m3/hr, mixes thoroughly with the smoky air, and exits the enclosure at the same rate. If there are 0.085 mg/m3 per ppm of formaldehyde, determine the concentration of formaldehyde gas (in ppm) in the enclosure at steady-state