Top Catagory Report

Summary

Question on how to do counts

Content

I need a push in the right direction.   I'm sure this is a newby question, but I can't quite figure it out.

I've been tasked with creating a report that shows the top 10 categories broken down by how they came to us.  (Email, Phone, Chat or Portal)

I started by creating a column and using "Decode" with the Source Level 2 field, I can create a field I call "Source" that defined how my organization likes them.    But here is where I get a little stuck.   I'm not sure how to do counts base on this field AND the category field.