premise: An upholsterer will do seven jobs—N, O, P, S, T, U, and X—during a given week on Monday through Friday. Each job is done on exactly one of the days, and no two jobs are done concurrently. Each job takes either one half day or an entire day. The following conditions apply: N is done on the same day as S. X is done on Wednesday, and T is done on Friday. S is done earlier than the day on which P is done. U and X are the only jobs that must take an entire day each. If P is not done on Friday, which one of the following must be true?
hypothesis: O is done on the same day as either P or T.