The price elasticity of ______ measures how responsive the quantity sellers are willing and able to sell is to changes in price.

There are 6 firms in a market and the market shares of the firms are 40 percent, 30 percent, 10 percent, 8 percent, 7 percent, and 5 percent. The four-firm concentration ratio is equal to

A) 2738. B) 2664. C) 100. D) 88.

Suppose Will gives his wallet containing $100 to Alex to hold while he works out. During Will's workout, Alex uses the $100 to pay his mechanic who fixed his scooter. The mechanic then took this $100 to his vet to pay off his account for rescuing his pet bird. The vet then used the $100 to pay Alex for money she owed him for tutoring her in economics. After Will's workout, Alex returns the wallet with the same $100 bill inside. Although the same $100 bill was used without Will's knowledge, everybody's debt has been settled. How much money was created?

a) $0 b) $100 c) $200 d) $300