Four couples play at the Knights and Liars Bridge Club. The four guys are Alex, Bert, Carl and Dave. The four gals are Alice, Betty, Carol and Diane. It is known that four of the eight are liars and the other four are knights. From the statements they make below, determine who are in each of the four couples.
Alex: I married Betty.
Bert: Carol married Carl.
Carl: Dave married Betty.
Dave: Diane married Alex.
Alice: Alex married Carol.
Betty: I married Carl.
Carol: I married Alex.
Diane: Dave married Alice.

Keeping the males constant, let's see what claims what about the partners of males
Males            Females
A                      B (says Male A) D (says Male D) C (say females A and C)

B

C                     C (says Male B) B (Says female B)

D                     B (says male C) A (says female D)


Now look at Male A's possible partners. Observe that we would get 4 liars 4 knights combination if and only if C is in fact A's partner. (Other wise no of liars is more)

So Male A and D are lying.

Since female C is male A's partner, C cannot me male C's partner, so Male B is lying.

So Female B is male C's partner.

So Male C is also lying.

So, finally all the males are lying.

Posted by Hardik on 2005-10-03 19:55:43