I see a few problems with the survey...
1) You have hidden questions with a "
Always hide this question" setting - this means that they are never rendered on the page. If you want them to dynamically control other questions, they must be hidden with a CSS class instead.
2) If using Expression Manager to set a hidden multiple-choice question, you need a separate equation question for every sub-question in the multiple-choice.
3) The hidden multiple-choice question and equation questions must be on a page following the array question.
4) The equation questions must be placed after the multiple-choice question.
Sample survey attached: