by aileenann Sun Oct 17, 2010 9:03 pm
Hello!
Yes, so if you are talking about question # 6, all the answer choices have F going first, so now we know we can't have K since K can't go before F and therefore K can't be in this particular setup. So we certainly had to consider the 5th constraint to get to this conclusion.
As for the 6th constraint, if M is tested, so are F and H, here it's not quite clear we need to worry as much about this, at least not directly. We know
M tested -> F tested & H tested
and we also know the contrapositive"
F not tested or H not tested -> M not tested
We don't know yet whether M is tested or what is going on with H, so we don't know if this constraint comes into play. It will become a mandatory rule we need to worry about if one of the triggers is set off. In this case, the trigger would be M being tested or H not being tested (since we know F is tested, we don't need to worry about that part of the trigger).
That said, for an orientation question, I'd generally recommend that you go through by applying all of the rules and systematically using them to eliminate answer choices in the ordinary course.