The amount, A (in liters), of oxygen used by a person's bloodstream varies directly with the amount, 1 (in liters) that is inhaled. At rest a normal person inhales about 12.5 liters of oxygen per minute, of which about 0.5 liters is absorbed by the blood
through the lungs and the rest is dispelled when the person exhales. The maximum
amount of oxygen that a person's body is capable of using is about 3.5 liters per
minute. At this rate, how much oxygen would be inhaled each minute?