In a family, there are six members A, B, C, D, E and F. 

A and B are a married couple, A being the male member. D is the only son of C, who is the brother of A. E is the sister of D. B is the daughter-in-law of F, whose husband has died. How is E related to C ? 

Brother

Justification: Daughter of uncle's father -- Uncle's sister -- Mother;
Mother's son -- Brother.

My only son's sister is my daughter
father of my daughter is me only
her brother means she is my 'sister'.

"G is father in law of D"
G+H means G is father of H
H is either son or daughter of G
H-R means H is sister of R
R@D means R is wife of D
so H and R are sisters
and daughters of G
so husband of R i.e. D is son in law of G
or G is father in law of D

Here the P is the wife of Q who is brother of T who is daughter of U.

That implies P is wife of U's son Q => U is father-in-law of P.

Q's mother is sister of P and daughter of M => P is the child of M.
S is daughter of P and sister of T, so P is parent of T too.
M ----> parent --------> P ------------>parent -------------> T
But given M is brother of R => M is male.

So, M is grandfather of T.

Brother of person's wife → brother-in-law of the person. Hence, the son of lady's brother is brother-in-law of the person.

Therefore, the brother of the lady is the father-in-law of the person. Hence, the lady is the sister of the person's father-in-law.

Man's son's sister---Man's daughter.
So, the man's daughter is the mother of the woman's husband. Thus, the woman's husband is the grandson of the man in the photograph.