The air tanks used by a certain fire department each contain 60.0 L of air at a pressure of 200.0 atm and a temperature of 293 K. Assume the average fire fighter exhales 0.500 L of air per breath at a temperature of 310.0K, exhales 30.0 times per minute, that the exhaled air is at a pressure of 1.00 atm, and that the air behaves as an ideal gas. Calculate the time in hours before a fire fighter using such an air tank runs out of air.