The Publisher of an Economics Textbook Finds That When the Book's

Multiple Choice

The publisher of an economics textbook finds that when the book's price is lowered from $70 to $60, sales rise from 10,000 to 15,000.Using the midpoint method, the price elasticity of demand is:

A) 500.
B) 50.
C) 3.5.
D) 2.6.