But that question is intentionally ambiguous so I think people fallback to whatever they were taught: traditional order of operations or the PEMDAS rule.
Don't you mean, the BEDMAS rule? 
Which I might add produces the "correct" answer:
6/2(1+2) = 6/2(3) = 3(3) = 9
Interesting. I voted 9 but my calculator says 1 for 6/2(1+2) without the multiplication sign. It's 9 for 6/2*(1+2). Didn't even know it made a difference.
Wow, this is reminding me of the dress issue. But this is math! It is very concise. How is it left to interpretation?
Because the problem is all about syntax (and there are many of those) and nothing about semantics. It's not a math problem, just a besserwisser quiz.
[edit]
Oh, didn't realize there where hundreds of answers in this topic, with many "proofs" of the true grammar of language. 
openwar - the real-time tactical war-game platform
For the late-comers to the thread, try read through it :)
I think we already covered everything regarding different syntax conventions, BEDMAS/PEMDAS and the pitfalls if you just try to follow it without understanding it, the logic behind the operator ordering (its not just a convention, even though the syntax is), and more...
I just found some interesting information in a book called "How to Think Like a Computer Scientist" that talks about order of operations for Python.
Parentheses have the highest precedence and can be used to force an expression to evaluate in the order you want. Since expressions in paren- theses are evaluated first, 2 * (3-1) is 4, and (1+1)**(5-2) is 8. You can also use parentheses to make an expression easier to read, as in (minute * 100) / 60, even though it doesn’t change the result.
Exponentiation has the next highest precedence, so 2**1+1 is 3 and not 4, and 3*1**3 is 3 and not 27.
Multiplication and Division have the same precedence, which is higher than Addition and Subtraction, which also have the same precedence. So 2*3-1 yields 5 rather than 4, and 2/3-1 is -1, not 1 (remember that in integer division, 2/3=0).
Operators with the same precedence are evaluated from left to right. So in the expression minute*100/60, the multiplication happens first, yielding 5900/60, which in turn yields 98. If the operations had been evaluated from right to left, the result would have been 59*1, which is 59, which is wrong.
They call me the Tutorial Doctor.
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Got rekt so hard, i blame that i am tired 
The Wanderer - Lost in time:
http://en.sfml-dev.org/forums/index.php?topic=14563.msg102482#msg102482
