1.Joanna is running for senior class president. She asks her peers to complete a survey ranking the following in order of importance to them: sports, clubs, test scores, prom, school lunch quality, administrative consequences, and study halls.

a).How many different rankings are possible?

b).What fraction of the possible rankings put test scores first?

2.How many more possible arrangements can be made using the letters of the word PERMUTATIONS than using the letters of the word COMBINATIONS? Justify your answer.

3.A blood bank needs twenty people to help with a blood drive. Twenty-five people have volunteered. How many different groups of twenty can be formed from the twenty-five volunteers?