premise: Five candidates for mayor—Q, R, S, T, and U—will each speak exactly once at each of three town meetings—meetings 1, 2, and 3. At each meeting, each candidate will speak in one of five consecutive time slots. No two candidates will speak in the same time slot as each other at any meeting. The order in which the candidates will speak will meet the following conditions: Each candidate must speak either first or second at at least one of the meetings. Any candidate who speaks fifth at any of the meetings must speak first at at least one of the other meetings. No candidate can speak fourth at more than one of the meetings. If S, T, and U speak second at meetings 1, 2, and 3, respectively, which one of the following must be true?
hypothesis: The fifth speaker at at least one of the meetings is either Q or R.