College students often buy cheap pizza because it is more affordable. suppose after graduating, college students find high-paying jobs. the demand for cheap pizza will likely:

The demand for cheap pizza will decrease because demand for cheap pizza is negative related to income.

a relation could be considered as negative if the correlation between two events opposing one another. As students finds high paying job, they are now able to buy more expensive pizza, which means that a number of customers for cheap pizza will be decreased