C, D, E, F, G, H, and I are the father, mother, aunt, brother, sister, wife and daughter of J, but you do not know which is which. But you know that:
- E and F are the same gender.
- C and D are of different genders.
- H was born before C
- F is not the mother of J.
Referring to the above information, which one of the following must be true?
- C is female.
- D is female.
- E is female.
- F is male.
- H is male.
Note that there are only two males among C, D, E, F, G, H, and I. Now E and F are the same gender. Consider the case that they are male. This would imply rest are female and this would contradict that C and D are of different genders. So E and F should be female
'E is female' must be true