A + B means A is the son of B;
A - B means A is the wife of B;
A x B means A is the brother of B;
A ÷ B means A is the mother of B; and
A = B means A is the sister of B.
What does P + R - Q mean ?

A. Q IS THE FATHER OF P.

All the six members of a family A, B, C, D, E and F are travelling together. B is the son of C but C is not the mother of B, A and C are a married couple. E is the brother of C. D is the daughter of A. F is the brother of B. How is E related to D ?

C. UNCLE

All the six members of a family A, B, C, D, E and F are travelling together. B is the son of C but C is not the mother of B, A and C are a married couple. E is the brother of C. D is the daughter of A. F is the brother of B. Which of the following is a pair of females ?

D. AD

K is the brother of N and X. Y is the mother of N and Z is the father of K.
Which of the following statements is not definitely true ?

E. N IS THE BROTHER OF X.

Pointing to a person, a man said to a woman, "His mother is the only daughter of your father."
How was the woman related to the person ?

A. AUNT