Indoor air quality is an under appreciated health hazardous. The air quality in a building can be modeled as a CSTR. Suppose that the carpet in a new office building releases formaldehyde at a rate of 10 micrograms per hour. The building has a floor area of 72 square feet. What ventilation rate (in cubic meters per hour) is needed to maintain a formaldehyde concentration of 0.1 parts per billion. (The density of air at room temp. is roughly 1.2 kg/m^3.) Be careful about the concentration units in the problem. You need to estimate one quantity to solve.