If i had a website with 20 links pointing to say "website.com" just an example! With 20 different anchor texts, which would Google use? Or would Google use all of them?
What do you mean which would Google use? Google would pick up all the backlinks, but since you spread them out throughout different 20 anchors you'll rank lower for each anchor text used in.
Yes it will use all anchors..but if you are targetting some keyword better use that in all your anchor text..to get good weightage..for that keyword
Google would use all of them but the ranking would not be that great, if you used same anchor on 20 diffrent sites then your SERP would boooooooooooooooooooost up