A system where goods and services are exchanged directly without a common unit of account is called the:

Suppose the firms in a perfectly competitive industry are earning positive economic profits

How will these positive profits affect the flow of resources into the industry? How will the equilibrium quantity and price change in the industry because of the profits?

The exchange rate is

a. the rate at which goods will exchange for each other in the international market b. the number of units of one currency required in exchange for one unit of another currency c. the number of units of one currency required in exchange for one unit of another countries' good d. established by the ratio of the values of currency to goods e. set by each individual country, which is why we have deficits and surpluses on current account