The first has about 6 times the number of upvotes (for the question and accepted answer)... so 66 total upvotes vs 12 upvotes.
I tend to only trust answers with >10... and preferably >20. So I am very comfortable with the first question/answer.
But according to the "duplicate" votes I should be ignoring completely all the upvotes and going straight to the answer with <10 upvotes.
So I think the one with more upvotes should be the authoritative question and the other one be marked as duplicate.
I have come across this sort of thing before on Stack Overflow and other Stack Exchange sites. What is the accepted canonical way to handle this sort of thing.