Step 1: Understanding the Concept:
This is a conditional question asking what must be true if P and Y are scheduled in the same month. We must consider all possible months for the P-Y pair and see what conclusion holds in every case.
Step 2: Detailed Explanation by Cases:
Let's analyze the three possible months for the {P, Y} pair. The other four experiments are R, T, X, Z.
- Case 1: {P, Y are in August.}
- August: {P, Y}
- Rule 1 (R in Aug/Sep): August is full, so R must be in September.
- Rule 2 (T in Sep/Oct): T must be in September or October.
- The remaining experiments to place are R, T, X, Z in Sep and Oct. We know R is in Sep.
- If T is in September, then Sep would be {R, T}. The remaining two experiments, X and Z, would go in October. This violates Rule 4 (X \textless Z), as they would be in the same month. So T cannot be in September.
- T must be in October.
- The schedule so far: Aug:{P,Y}, Sep:{R,\_}, Oct:{T,\_}. The remaining experiments are X and Z.
- To satisfy Rule 4 (X \textless Z), X must go in September and Z must go in October.
- The only possible schedule is: Aug:{P,Y}, Sep:{R,X}, Oct:{T,Z}. In this case, R and X are in the same month.
- Case 2: {P, Y are in September.}
- September: {P, Y}
- Rule 1 (R in Aug/Sep): September is full, so R must be in August.
- Rule 2 (T in Sep/Oct): September is full, so T must be in October.
- The remaining experiments are X and Z. The open slots are one in August and one in October.
- To satisfy Rule 4 (X \textless Z), X must be in August and Z must be in October.
- The only possible schedule is: Aug:{R,X}, Sep:{P,Y}, Oct:{T,Z}. In this case, R and X are in the same month.
- Case 3: {P, Y are in October.}
- October: {P, Y}
- Rule 2 (T in Sep/Oct): October is full, so T must be in September.
- Rule 3 (T \(\neq\) X): Since T is in Sep, X cannot be in Sep. X must be in August.
- The remaining experiments are R and Z. R must be in Aug or Sep (Rule 1).
- If R were in September, Sep would be {T, R}. August would have X and Z. But this violates Rule 4 (X \textless Z). So R cannot be in September.
- R must be in August.
- The schedule so far: Aug:{X,R}, Sep:{T,\_}, Oct:{P,Y}. The only remaining experiment is Z, which must go in September.
- The only possible schedule is: Aug:{R,X}, Sep:{T,Z}, Oct:{P,Y}. In this case, R and X are in the same month.
Step 3: Final Answer:
In all three possible cases, R and X must be performed in the same month. Therefore, statement (B) must be true.