A textile finishing process involves drying a fabric that has been treated with a volatile solvent. The wet fabric entering the dryer contains 45% solvent, and the dried fabric contains 3% of the entering solvent. Solvent-free air enters the dryer at a rate of 8 pounds per pound of solvent -free fabric. The solvent has a molecular weight of 60.
Calculate the percentage of solvent in the dried fabric by weight; and the concentration of solvent in the dryer exhaust in mg/m^3 if the exhaust is at 160 deg F and 1 atm.