A, B, C, D, E, F and G are the members of a family consisting of 4 adults and 3 children, two of whom, F and G are girls, A and D are brothers and A is doctor. E is an engineer married to one of the brothers and has two children. B is married to D and G is their child. Who is C?

It is given that B is married to D and their child is G. Also, E is married to the one of the 2 brothers A and D. As D is married to B, E is obviously married to A. That leaves us with F and C. It is also said that E has two children. So, we can clearly infer that the 2 children are F and C.

Now, it is given that there are 3 children of whom only 2 are girls i.e. F and G. This means sex of C is male.

C is A and E's son.