Checkbox counter

Hi everyone
Im new to Axure. I previously spent time developing an app using JustInMind, but this had limitations (no resizing for checkboxes or resizing for different screen sizes).

I wanted to find out a step-by-step guide of how to count ticked checkboxes in the Axure. I’ve tried searching the forums but it doesnt make sense. Please see attachment.

Thanks

test.rp (46.3 KB)

Demo: https://567ru0.axshare.com/#c=2
Source file: Counter.rp (62.4 KB)