How can I control the value of the variables for a result slide?

Hey Gurus,

In my course, the learner can take 3 different paths; content A, content B, and content A+B

There are 2 quizzes (one for path A, one for path B).  The learner will take both quizzes if they want to take both paths.

I have 3 result slides (one for Quiz A, one for Quiz B and then a final result).

I want to manipulate the value of the final result based on the path that the learner took and their results on Quizzes A and B.    When I try to create a trigger to adjust the variable, it's not available to me.  How can I get to it?

Thanks for any help.

Liz