On each of the last five nights, a Karsakov brother played Chess against a different Grand Master. Each brother won a different number of games, from one to five. When questioned on Saturday morning, the brothers gave the following answers.

A. "Nikolai played last night" said Boris. "Grand Master Markovich lost 4 games on Wednesday night."
B. "Rubbish!", screamed Victor. "It was the next night that Markovich lost 3 games. My opponent was Grand Master Karsokovich."
C. "I think you will find," interrupted Alexis, "That it was I who took on Markovich. I can't remember how many games I won but I know it was 2 more than my brother Vladimir. Boris played against Grand Master Ivanovich the night before I played. And Tuesday my Karsokov brother could only win 1 game."
D. "Alexis you are not being honest," said Nikolai. On Thursday night my brother won four games. I won 2 more games than Boris but not against Grand Master Grigorovich."
E. "Alexis," chimed in Vladimir, "Your words are false as always. And it was Grand Master Petrovich who played on Thursday."

Each brother is either a consistent truth teller or a total liar.
On what night did each of the brothers play, who was their Grand Master opponent and how many games did each brother win.

(In reply to Solution - spoiler by Sara)

Sara, if the meaning of this particular 2 sentences (Alexis: Boris played against Grand Master Ivanovich the night before I played. And Tuesday my Karsokov brother could only win 1 game) is supposed to be the one that you infer, then the problem would have one solution, the one that you suggest.

However, from my experience encountering other logic problems, I have understand that such wording is commonly used as neutral. Neither reffered for the same person, neither for a different person.

Actually, in an every day life situation, a statement like that would be perceived as talking for the same person, because it uses the words "And" for introduction and "my brother". If we wanted to point out that the person in the second sentence is different from the first, we would not start with "And" and we would say afterwards "another Karsokov brother of mine". If we wanted to be ambiguous about the identity of the reffered person, then again we would not start with "And" and we would say "a Karsokov brother of mine".

Well, English is not my mother tongue, so I can not be sure for what I have just said, but it is what I believe.

Posted by Magda on 2006-02-19 19:23:41