One of four people - two men (Ben and Carl) and two women (Dorothy and Evelyn) - was murdered.

The following facts relate to the people mentioned:

(a) Ben's sister argued exactly once with Dorothy's legal husband after the murder.

(b) Carl's sister argued twice with the victim's legal spouse after the murder.

Who was the victim?

The problem here is that people automatically assume that there are two married couples. This assumption, however, is a problem. If you followed that assumption, either Ben or Carl could be the victim; it does not prove anything.

However, if Ben and Carl are brothers and have the same sister, then you get your answer. Dorothy has to be married because of (a), thus  the sister has to be Evelyn.

Following the logic, the victim has to be Dorothy.

Posted by Kell on 2012-08-18 16:51:04