Question

what is the effect on the market price and output of hamburgers with reference to an increase in the income of consumers

Answer 1

If hamburger is a normal good, then increase in the income of consumers will increase the demand for hamburgers, as a result both market price and output of hamburgers will increase.

But if hamburger is an inferior good, then increase in the income of consumers will decrease the demand for hamburgers, as a result both market price and output of hamburgers will decrease.