If you run 100 meters in 10 sec, what is your average speed?

How do you use the elimination method for this question? explain, because i really want to understand!

Mrs. morton has a special reward system for her class. when all her students behave well, she rewards them by putting 3 marbles into a marble jar. when the jar has 100 or more marbles, the students have a party. right now, the the jar has 24 marbles. how could mrs. morton reward the class in order for the students to have a party?

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?