Demand

The law of demand refers to how

• demand changes when people's incomes change
• demand changes when the prices of substitutes and complements change
• the quantity demanded changes when the price of the good changes
• the price of the good changes when people's demand for the good changes

The diagram represents a

• increase in demand
• decrease in demand

A new study has shown that avocados are extremely healthy. The demand for avocados has increased due to a change in

• market size
• price of a substitute good
• price of a complementary good
• tastes and preferences 

The phrase "a change in demand" most directly implies a 

• movement along the curve
• movement along the price curve
• change in quantity demanded of a good
• shift in the demand curve

The law of demand states that as the price increases then 

• quantity demanded increases
• quantity demanded decreases
• demand increases
• demand decreases

A change in the demand for apples could result from any of the following except

• a change in the number of buyers
• increased preferences for fresh fruit consumption for health reasons
• a change in the price of an apple
• a change in the price of a banana

Iceberg & romaine are two different types of lettuce. For most consumers, iceberg and romaine are 

• complements
• substitutes
• inferior goods
• resources

If the demand for used cars decreases after the price of a new car falls, used cars and new cars are

• inferior goods
• substitute goods
• complementary goods
• normal goods

If the demand for a good increases when people's incomes increase, 

• the good is an inferior good
• the law of demand is violated
• the good's demand curve must be upward sloping
• the good is a normal good

If Mary used to buy 10 units at $4 each and now buys 15 units when the price is $4, her

• quantity demanded has increased
• quantity demanded has decreased 
• demand has increased
• demand has decreased