(i). Seven students P, Q, R, S,  T, U and V take a series of tests.
(ii). No two students get similar marks.
(iii). V always scores more than P.
(iv). P always scores more than Q.
(v). Each time either R socres the highest and T gets the least, or alternatively S scores the highest and U or Q scores the least. If S is ranked sixth and Q is ranked fifth, which of the following can be true ?

Answer: D. U is ranked third or fourth.

In terms of scores, we have :
V > P, P > Q  i.e. V > P > Q.
If R scores the highest, we have R > ...... > T,
If S scores the highest, we have S > ...... > Q or S > ...... > U.

If S is ranked sixth and Q is ranked fifth, we have :
? > ? > ? > ? > Q > S > ?.

In the case, R will rank the highest and thus T will rank the least.
We have :
R > ? > ? > ? > Q > S > T.

Also. the roder V > P > Q will be maintained i.e. V and P will have second, third or fourth places. So, statements (a), (b), (c) and (e) cannot follow. Thus, (d) is the answer.