Simple Economics Problem?

The student must fail the test.On the market, we don't even know which one is supply and which one is demand,because what is bought,is sold. They have ignored to check the inventory of the tobacco industry which they will find that some cigarettes have not been brought to the market because the price is too low. In front of the store,they might observe consumers who offers more higher price than the ceiling to get more cigarettes. That is the shortage they should know.