(i).   P, Q, R, S, T and U are six members in a family in which there arfe two married couples.
(ii).  T, a teacher is married to the doctor who is mother of R and U.
(iii). Q, the laywer is married to P.
(iv). P has one son and one grandson.
(v).
  Of the two married ladies one is a housewife.
(vi). There is also one student and one male engineer in the family. How is P related to R ?

Answer: D. Grandmother

One couple is QP.
Now, R and U are the children of T. So, the other couple is TS.
T is a teacher.
S is a female doctor.
Q is a lawyer.
Clearly, P is a housewife and hence a female.
S is the mother of R and U.
P has one son and on grandson.
Clearly, T is the son of P and R or U is the grandson.
The grandson is a male engineer and the grand-daughter is a student.

Hence, P is the grandmother of R.