Any help would be greatly appreciated!

My final is today and there are two questions I am completely stuck on in my homework which I know will be on my final. So if any of you are good at math I could totally use the help with these two problems:

1. Sarah's overall average in Physics was 93%. Her average was based on 4 exams each worth 100 points and a final worth 200 points. What was the lowest possible score she could have made on her first exam?

2. Kelly and Karen each have an average of 75 on the six exams given in botany. Kelly's scores have a small standard deviation while Karen's scores have a large standard deviation. Give an example of scores for Kelly and Karen that illustrate this situation.

I am taking an online class so I haven't been able to see these worked out. Please tell me how you got to the answer because I want to learn.

1. The total points received that would give Sarah a 100% is 4*100+200. Imagine she had a 93%, how many total points would she have? Now, suppose that she received that many points in the class and she got perfect scores on all of her exams but the first one. How many points did she get on the first exam?

2. Make sure you understand what standard deviation means. Now, you just have to make up six imaginary exam scores that average out to 75. I would use the most extreme examples possible.

For instance: Let's say that me and you both took two exams. I scored 50 on both exams, and you scored 100 on one and 0 on the other. What are our averages and standard deviations?