The sisters of Aaron Green were Betty and Clara; the name of Aaron's girlfriend was Flora Brown and, Duane and Edwin were Flora’s brothers. Their occupations were as follows:

• Aaron was a doctor.
• Betty was a doctor.
• Clara was a lawyer.
• Duane was a doctor.
• Edwin was a lawyer.
• Flora was a lawyer.

One of the six killed one of the other five. Here are some clues to the murder.

1. If the killer and the victim were related, the killer was a man.
2. If the killer and the victim were not related, the killer was a doctor.
3. If the killer and the victim had the same occupation, the victim was a man.
4. If the killer and the victim had different occupations, the victim was a woman.
5. If the killer and the victim were of the same sex, the killer was a lawyer.
6. If the killer and victim were different sexes, the victim was a doctor.

Who was the killer? Who was the victim?

I created a series of 6x6 matrices numbered 1 thru 6 for each of the six rules, grouping them into three pairs.  Each cell was filled with either T or F according to the stipulations for each rule.  From the first two rules, it is clear that neither Clara nor Flora could be the killer since neither was a man or a doctor - the results of rules 1 and 2 respectively.

I then wrote logic comparing the cells in each pair, looking for a 'T' in either corresponding cell for each pair.  All three pairs must have at least one 'T' for each cell position.

The only combo that returned a 'T' for all three pairs was Betty as the killer and Duane as the victim.

Posted by hoodat on 2012-12-19 00:33:59