math
posted by kevin on .
A school has 6th, 7th and 8th period Social Studies classes. One student from each class will be chosen to represent the school in an essay contest. The 6th period finalists are Mike, Sara, Luis and Ed. The 7th period finalists are Ben, Eric, and Sandy. The 8th period finalista are Hilda, Liz and Rob. How many different ways can the students be chosen?

periods
│6│7│8│
no. of students for each of those periods:
4*3*3
so the number of ways is 36