A teacher has three (3) test papers with no names on them. He looks in his grade book as well as notices that exactly three students are missing test scores. At this point, he assigns one of test papers to each of the three students.
a.) How many manners can he assign the papers to the students?
b.) How many manners can he assign the papers to the students if each receives the correct paper?
c.) How many manners can he assign the papers to the students if only one of them receives their correct paper?
d.) How many manners can he assign the papers to the students if none of them receives the correct paper?