In each of the following situations, identify which of the 11 principles is at work.

a. You choose to purchase your textbooks online rather than pay a higher price for the same books through your college bookstore.

b. On your spring break trip, your budget is limited to $35 a day.

c. To help reduce traffic congestion, many states have adopted congestion pricing. Under this program, drivers are charged more to use express lanes during peak rush hour.

d. Congress passes an infrastructure bill to help construction workers who were left jobless after the last recession.

e. You buy a used textbook from your roommate. Your roommate uses the money to buy songs from iTunes.

f. You decide how many cups of coffee to have when studying the night before an exam by considering how much more work you can do by having another cup versus how jittery it will make you feel.

g. There is limited lab space available to do the project required in Chemistry 101. The lab supervisor assigns lab time to each student based on when that student is able to come.

h. You realize that you can graduate a semester early by forgoing a semester of study abroad.

i. At the student center, there is a bulletin board on which people advertise used items for sale, such as bicycles.

Once you have adjusted for differences in quality, all the bikes sell for about the same price.

j. You are better at performing lab experiments, and your lab partner is better at writing lab reports. So the two of you agree that you will do all the experiments and she will write up all the reports.

k. Amazon announces a program to develop a drone delivery system in place of traditional ground shipping.