Time to end this little argument, you all agree that you start with 10 points so I won't set that up. Here is exactly what the test giver guy points to on the board as translated in the Anbu_Aone episode 24 with the written chuunin exam.

"Example 1. All problems correct -> Your point total remains at 10
Example 2. Three problems incorrect-> Your point total is reduced to 7"

From that info Naruto is the only one doomed to fail as he answered none of the questions at all. Every teacher I've ever had in my life marks a question wrong if you don't answer it. From that info Naruto DID fail the test as he got 0 out of 10 points and he just got lucky because he is gutsy and was willing to bet it all on the last question. Damn, how come none of you had the 5 minutes to watch the episode again yourself? I registered just to stop this argument.

Oh and he's not exactly a genious he was the only one that didn't notice the test was to test your info gathering skills not you knowing how to do the problems on your own.