I can't believe that 21% have currently got it completely wrong, thinking that OR has precedence over AND! Hopefully they're just all misunderstanding what 'precedence' means 😉
It seems more likely that they've misunderstood what MicroSoft means by "higher" on the BoL Page Operator Precedence. The question is sensibly phrased, using "has precedence over". The BoL page says "An operator on higher levels is evaluated before an operator on a lower level", and then provides a table with AND on level 6 and OR on level 7. It would not be unreasonable for people to think that level 7 is a higher level than level 6, and perhaps that accounts for the 21% very wrong answers. But level 7 is lower than level 6, as anyone who looks at the page layout (the right way up) can tell :w00t:.
On that BoL page, a "higher" level is the one introduced closer to the top of the page, not one with a higher level number. Since the table is printed starting with level 1 at the top and continues in nummerical order of level number, the "higher level" is always the level with the lower number.
The various BoL pages on this topic from SQL 2000 onwards have all misused "higher" in this sense; it was pointed out to MS about 12 years ago, but they think it's OK :crazy:. Perhaps they speak a different English in Redmond. 😉
Edit: it is of course to be hoped that none of the people thinking OR has precedence over AND has ever written any T-SQL that depends on that misunderstanding - or if they have, that they wrote it so recently that they haven't yet done any unit testing!