Suppose the price of apples decreases from $1.00 to $0.80 each and, as a result, the quantity of apples demanded increases from 800 to 1,000 . Using the midpoint method, the price elasticity of demand for apples in the given price range is

The cross elasticity of demand for strawberry jelly and grape jelly is likely to be

A) positive because they are substitutes. B) positive because they are complements. C) negative because they are substitutes. D) negative because they are complements. E) negative because they are inferior goods.

In the above figure, Mark's monthly budget line for movies and plays changed, as shown by the arrow. The change was caused by

A) a decrease in Mark's income. B) an increase in Mark's income. C) a fall in the price of a play. D) a rise in the price of a play.