Adding variable together to direct to different endings

Hello all,

I’ve been struggling to find an option to add more than two variables together to direct respondents to different endings.

Basically what we need to do can be summarised as below:

The current setup of the quiz as it stands is that questions 1 to 5 are added to each other and then directed to the appropriate ending (see ending scores below).

• Add up the scores from questions 2, 3, and 5 to get subtotal 1. 
• Subtract the score on question 1 from 8 to get subtotal 2.
• Subtract the score on question 4 from 8 to get subtotal 3.  

Add subtotal 1,2,3 together to get the final score.

• Score of 0 to 15 links to ending A 
• Score of 16 to 30 links to ending B 
• Score of more than 30 links to ending C

 

How do we add @subtotal3 to above equation?