Suppose a new textbook sells for 100 at the college bookstore. ...

[Yolanda]

Suppose a new textbook sells for 100 at the college bookstore. The bookstore will buy it back at the end of the semester for 35, and sell then it used to somebody else for 75. Christina agrees to the deal, and pays 100.
 
  Once she buys the book, her sunk cost is A) 25.
  B) 35.
  C) 40
  D) 65
  E) 100.

Question 2

A positive externality ________.
 
  A) gives rise to external benefits
  B) leads to increasing returns to scale
  C) imposes an additional cost on the society
  D) leads to higher economic profit

[reversalruiz]

Answer to Question 1

D

Answer to Question 2

A