Scoring Help for multi answer question

I am building a 25 question survey.  Each question will have a list with an option to answer Yes, No or Not applicable.  I am unclear how to get the survey to score these. In the following example, the person completing the survey must answer a-d and depending on how they answer, I need the question to score as total answered yes over total answered Yes/No.  So they may have 0-100% on this question. I will repeat this on 25 questions and then need the total of all questions.  

Example:

1. Common Information Screen                   Yes                No            Not Applicable

             a. Pay plan

             b. fees

             c. customer name

             d. customer address