The following graph shows the rate of inhalation of oxygen (in liters per minutes) by a person riding a bicycle very rapidly for 10 minutes. Estimate the total volume of oxygen inhaled in the rst 20 minutes after the beginning of the ride. Use rectangles with widths of 1 minute and use the center point of each subinterval to determine the height. E) Liters per minute The total volume of oxygen inhaled is about D liters.