Doctor P visits in between which of the following pairs of doctors ?
Answer: D
We first form the sequence of visit using (iv), (v) and (vi).
From (iv), we know that Q visits first and U visits last.
From (v), we know that W visits first after break and is followed by R.
From (vi), we know that P visits after break.
Thus, the sequence of visit after break becomes W R P U.
Also, S has the same position in morning session as P in afternoon session. So, sequence of visit before break is Q, T / V, S, V / T.
Clearly, P visits between R and U