In 1997 LA County air had carbon monoxide (CO) levels of 15.0ppm. Average human inhales about 0.50 L of air per breath and takes about 20 breaths per minute. Explain how many milligrams of carbon monoxide does the average person inhale in a 6 hour period for this level of carbon monoxide pollution? Presume that carbon monoxide has a density of 1.2g/L.