Oh my gosh -- do your own homework! How else are you going to learn. If you honestly do not know how to figure out the above diagrams - Ask (or get) a tutor or simply ask your teacher to teach this to you!
sure does sound like homework and i don't feel like thinking that hard right now!
The market at point a will be higher than at point b? Is higher the word. Urgh. If I do your homework can I get the marks for it?