One of Mr. X, his wife, their son and Mr. X's mother is an Engineer and another is a Doctor.
1. If the Doctor is a male, then the Engineer is a male.
2. If the Engineer is younger than the Doctor, then the Engineer and the Doctor are not blood relatives.
3. If the Engineer is a female, then she and the Doctor are blood relatives.
Can you tell who is the Doctor and the Engineer?

As previous posters have mainly pointed out, we cannot assume that the wife and mother-in-law are not blood relatives or even that the Mr X and his wife are not blood relatives (heard of 'kisssing cousins?).

Nor can it be assumed that the wife is younger than the husband or indeed than the mother-in-law.

This leads to so many solutions that it can hardly have been the writer's intention! The obvious implicit assumptions on age and relationships do give only one solution though - Mr X as engineer and son as doctor.

Posted by dmm on 2003-08-28 02:06:45