Hi, for drills like this that are asking us for the conclusion, we would want to link the two premises together using the thing they have in common. Since we know that all Es are F from the contrapositive of the second premise, we can link this with the first one. We know that most D are E, and since all Es are also F, we know that most Ds are also F.
For missing premise drills, we are trying to prove that the conclusion is true based on the existing premise. We will likely need to link the existing premise to the conclusion with the right answer.
