Mr. Burton has a wife and a daughter; the daughter has a husband and a son. The following facts refer to the people mentioned:
- One of the five people is a doctor and one of the other four is the doctor’s patient.
- The doctor’s first offspring and the patient’s older parent are of the same sex.
- The doctor’s first offspring is:
- not the patient, and:
- not the patient’s older parent.
Who is the doctor?
This time I do agree with Ady.
From clue 2, the Patient has a parent among the five, so the Patient must be the daughter or the daughter's son.
Also, from clue 2, the Doctor has a child among the 5, so the Doctor must be one of the four parents.
Assume the Patient is the son.
From clue 3a, the Doctor cannot be the daughter or her husband, so it must be Mr. or Mrs. Burton.
That makes the daughter the Doctor's first offspring, who cannot be the patient's older parent (from clue 3b).
So the husband is the Patient's older parent, but this contradicts clue 2.
Therefore, our assumption is wrong and the Patient is not the son.
Therefore, the Patient is the daughter.
From Clue 3a, the Doctor cannot be Mr. or Mrs. Burton.
Therefore, the Doctor is the daughter's husband.
This all checks out. Mr. Burton is the patient's older parent, the same sex as the doctor's son.
Edited on January 3, 2014, 1:22 pm
Analytical Solution (spoiler)
