Total costs increase from $1500 to $1800 when a firm increases output from 40 to 50 units. Which of the following are true?

Which one of the following is normally the cheapest way to address water shortages?

a. Expanded development of groundwater aquifers b. Desalination c. Building dams d. Water conservation efforts e. Creating a system of property rights

Tolls that drivers pay to use toll roads, the fares that riders pay on buses and trains, and the tuition that students pay at public universities are examples of the government making a good (Click to select)

a. rival b. nonexcludable c. nonrival d. excludable