P, Q, R, S, T and X are members of a family . There are two married couples. Q si an engineer and the father of T. X is the grandfather of R and is a lawyer. S is the grandmother of T and is a housewife. There is one engineer, one lawyer, one teacher, one housewife and two students in the family.
Which of the following are two married couples ?

Options

A. XS,QP
B. XS,QT
C. XS, RP
D. TS,RX

Answer

A

Explanation

The first two sentence are U.S.I. So is the last sentence. The third, fourth and fifth sentences make up the actual information. We begin with the 3rd sentence because it mentions a parent- child relationship . The diagram is :

Now, we should look for another sentence that involves either Q or T. The fifth sentence gives some information about T. It says that S is the grandmother of T. Note that if S is the grandfather of T, Then the son of S must be T.s father and hence Q is the son of S. Hence:

Now, the only information remaining is the fourth sentence . The diagram

Now, we see that we have ended up with two different components. To resolve this deadlock we make use of the U.S.I : " There are two married couples in the family " . Obviously, the two possible pairs are of grandfather, grandmother and father , mother. Hence, we combine the two diagrams into the following way :

The above is the logically explicable diagram for the problem. Note that the professions of P, T and R are yet unkonwn, However, with reasonable justification, we many assume that the mother (P) should be the teacher and the two children T and R should be students . But this conclusion can be challenged and without reason. Also , the sexes of T and R can.t be determined .