Answer:
b. product A and B are subtitutes
a. the quantity of fast food consumed decreases as income increases
Explanation:
Cross price elasticity of demand measures the responsiveness of quantity demanded of good A to changes in price of good B.
Cross price elasticity = percentage change in quantity demanded of good A / percentage change in price of good B.
The cross price elasticity of substitute goods are always positive because if the price of good B increases, the Quanitity demanded of good A rises.
Substitute goods are goods that can be used in place of another good.
Complement goods are goods that are used together. E.g. car and gas
Inferior goods are goods whose demand increases when income falls and whose demand falls when income rises.
I hope my answer helps you
