Economics Question, Please Help!!?

Ok, so I am not sure how you have been taught this concept of marginal ysis so my answer should be taken with a grain of salt. My understanding of margins begins with looking at things on a unit by unit basis. In this case it looks like you have time as a unit bags of chips as a unit and so on. yzing on the margin is to look at a situation and then to determine at which point something becomes worthwhile. So for example on question a, how many days can you wait before you do laundry? If you yze this marginally it then takes on this thought process: If I wait to do laundry for 3 days I can still have some clean clothes but if I wait 5 days I will have nothing clean to wear and can't leave the house. Does it become worth it to you to clean your clothes on the third day, the fourth day, or the fifth day? It really is a trade off such as you don't have time on the third day so it is better to do it on the fourth day and so on. Thinking marginally just means taking a situation unit by unit and determining at which unit it becomes either worth it or not worth it.