if and - if or statements

The questions are shown on the attached spreadsheet. There are 2 questions one on each sheet. As this is my first post feel free to let me know if I can make my questions any clearer. On the spreadsheet the yellow cells indicate data that I'd import ( on the left) and input by hand to get the process going.

The green cells have the correct numbers in them but I've had to manipulate them by hand.

I need help with the formula logic.

thanks,
jccamp