You are working on your car in your garage (volume 1,000 ft3). You suddenly realize that you should not have left the engine running and the room has started to fill with carbon monoxide. You will pass out from carbon monoxide poisoning if the the concentration is greater than 150 ppm. If the ventilation air flow rate in (and out of) the room is 100 ft3/min and the incoming gas concentration is 100 ppm, how long do you have to escape? (Please never work on a running car in a closed garage!)\