The answer to this question should be well structured with no more than 3-4 core points explained and develop. Start by considering the wording 'evaluate' this already tells you that you need to look for advantages and disadvantages of the price floor. Your first step should be to define key words : price ceiling , follow this by drawing a price ceiling on a classic demand and supply and explain the A-B-C-D of how the price ceiling works.You then need to begin on your evaluation. Think of 3 impacts a price ceiling might have, you must try to contextualise and add examples. Perhaps consider the impact on low income earners, the impact on the incentives of landlords, the assumptions made of a price ceiling . In each discuss the advantages and disadvantages before coming to a conclusion. To conclude ask your self 'With all I have said is a price ceiling a good decision or not?'