Muliple criteria Using Frequency and Match Formulas

[aboer13]

Hello,
I am trying to calculate the frequency how many of my students have responded in discussion boards. So first, I need to find a formula that will count the names excluding duplicates. I also want this formula to work if there are blank cells. Second, the students are all divided up between groups 1-5. What formula could I use that would tell me how many students that are replying from group 3.
Thank you!

 

[AhoyNC]

It would help if you would post a small example of how your data is laid out, but maybe one of the formulas below will help.
These are array formulas and must be entered with CTRL-SHIFT-ENTER.

Excel Workbook
	A	B	C	D	E
1	Group 1	Group 2	Group 3	Group 4	Group 5
2	Student1		Student4	Student1	Student1
3	Student2	Student4	Student3	Student2
4	Student3		Student3	Student3	Student1
5	Student4
6	Student5	Student5	Student3
7	Student6	Student6	Student4
8
9	6	3	2	3	1
10
11	6	3	2	3	1
Sheet