Which concept did Hugo Grotius address and construct in his published work of the 1600s, The Law of War and Peace?

An individual decides to rent an apartment for $7,000 per month. The commuting time from this apartment to his office is 80 hours per month

If the individual's opportunity cost of time is $30 per hour, calculate the direct cost, indirect cost, and total cost per month she would incur if she rents the apartment.

The above figure shows the marginal benefits and marginal costs of a college education. If colleges receive a $5,000 subsidy, then enrollment equals

A) 0. B) 10 million. C) 15 million. D) 25 million.