Your proposed scenario would violate Rule #1 - that there is at least one officer per committee (as there are none in your proposed Sales committee).
The quality committee has to have M or L in it because Rule #2 states that each employee must be assigned to at least one committee, and we know that at least one spot in each committee is reserved for an officer.
This gives us: P: F G H Q: (F/G/H) ___ ___ S: K, (F/G/H), ___
We need to place M and L in two of the remaining three spots. Since only one of these three spots is in S, we know that either M or L will have to be placed in Q.
Does that make sense? Please let us know if you have any other questions!