Val, Lynn, and Sam are related to each other, but not incestuously (i.e. siblings do not create a child).

1. Among the three are Val’s father, Lynn’s only daughter, and Sam’s sibling.
2. Sam’s sibling is neither Val’s father, nor Lynn’s daughter.

Which one is a different gender from the other two?

Either Lynn or Sam is Val's father.

1) Lynn is Val's father
Since Sam's sibling is not Val's father it can not be Lynn, thus Sam's sibling is Val.  Since Sam's sibling is not Lynn's daughter then that means Val must be a male.  Since Lynn must have a daughter, that makes Sam a female.  Finally, since Lynn is a father, that makes Lynn a male.  Thus the odd one out is Sam.

2) Sam is Val's father
This makes Sam a male.  Thus Lynn's daughter must be Val.  However, that does not leave a possible sibling for Sam without creating an incestuous relation.

Thus the odd one out must be Sam as we have:
Val: male, daughter of Lynn and brother of Sam
Lynn: male, father of Val and Sam
Sam: female, daughter of Lynn and sister of Val

Posted by Daniel on 2013-08-21 10:07:25