Question

A line passes through the origin and the point (8, 4). The x-axis represents time in minutes, and the y-axis represents gallons. What rate does the slope represent? A. 12 gallons per minute B. 0.5 minutes per gallon C. 2 minutes per gallon D. 0.5 gallons per minute

Answer 1

You know two points on the line: 
 
                 (0 minutes, 0 gallons)  and  (8 minutes, 4 gallons) .

The slope of the line is

                             (4 gallons - 0 gallons) / (8 minutes - 0 minutes) =

                                       (4 gallons)  /  (8 minutes)  = 

                                           (4 / 8)  (gallons / minutes)  =

                                               1/2  gallons/minute .