A) 12 pounds
B) 28 pounds
Step-by-step explanation:
Step 1 :
It is given that there is a fixed charge for every delivery and variable charge based on the distance.
The graph is plotted between distance (x-axis) and delivery cost (y-axis).
Step 2 :
A) The value of y corresponding to x=0 represents the total charge for a distance of zero miles. This value would be the fixed charge. By observing the graph we can conclude that y=12 when x=0. Hence the fixed charge is 12 pounds.
Step 3 :
B) By observing the graph we can conclude that the total cost for a distance of twenty miles is 40 pounds.
This includes fixed charge and variable cost based on the distance.
The fixed cost is 12 ponds.
Hence variable cost is 40 - 12 = 28 pounds. The delivery cost per mile is 28/20=1.4 pounds.
It is given that the distance between the distance for the 2 deliveries is 20 miles. The fixed cost is the same for both deliveries. The difference in variable cost would be 1.4*20=28 pounds.