LG Game 1 Question 5 Explanation, by LSATHacks
This question asks for a complete list of everyone who must perform in the afternoon. All of the answers have T, so we must only decide between W, Y and S.
In questions 2 and 4, we saw that W can go in the morning, with this diagram:
This diagram also shows that Y must go in the afternoon, because there’s no way to place WY any earlier without pushing Z into the afternoon, which violates rule 4.
The right answer to the first question, A, showed that S can go in the morning. So S, W, R and Z don’t have to go in the afternoon.
We’re left with: T and Y must go in the afternoon, and only T and Y. C is CORRECT.
Why couldn’t S go into the afternoon?
It’s not couldn’t. It’s MUST. Since S can go in the afternoon, that means it doesn’t have to go in the afternoon. The right answer is only people who must be in the afternoon, never in the morning.