math teaser, kinda tough

[AleoMagus]

The fireman is not the conductor's uncle. Yet you have:

[ QUOTE ]
john is conductor, toms nephew, petes nephew


[/ QUOTE ]

and since you also say that tom is the fireman, this makes this relationship between the two impossible. As Pete and Tom are brothers, this means that Tom must actually be John's Father.

Regards
Brad S