For the sake of people looking for a simple answer I'm going to make this easy.
If it's a simple calculation between two points (i.e. no other alternate):
PNR = (Flight Fuel - Extra Fuel Burnt on Climb) / (SGR Home + SGR Continue)
Dist to CP = (Total Distance x GS Return) / (GS Home + GS Continue)
If you have the memory of a sieve (like me) then for data dumping in the first few minutes of your exam these can be written in shorthand:
PNR = (FF-Climb) / SGR Sum
and
To CP = (Tot Dist x GS Ret) / GS Sum
Go forth and aviate,