Question

If as many of the experiments as possible must be performed between R and S,
which of the following must be true?

• A. \( \text{M is done fourth.} \)
• B. \( \text{P is done third.} \)
• C. \( \text{P is done fourth.} \)
• D. \( \text{R is done fifth.} \)
• E. \( \text{T is done fourth.} \)

Hint:

Maximize positions between R and S.

Answer 1

The Correct Option is D

Step 1: Constraints: T not 4th unless S 2nd, M 1st needs S or R 5th, R 5th bans P 3rd,
P before T; maximize experiments between R and S.
Step 2: R and S need 1-4 positions between, so R 1st, S 5th or R 2nd, S 6th, but 5 slots.
Step 3: R 1st, S 5th with M, P, T between (e.g., RMPTS) maximizes 3; R 5th, S 1st invalidates P before T.
Step 4: (D) R 5th ensures S 1st, maximizing others before.