Four pairs of lords and ladies all went to a royal ball. Each lord was wearing one color (yellow, red, blue, or green) and each lady was also wearing one of these colors. No couple was wearing the same color, so it was hard to tell who was married to who.

Using the clues, can you determine which lord is with which lady?

1. The Green Lord is with the Red Lady, if and only if the Yellow Lord is with the Blue Lady.

2. The Yellow Lord is with the Red Lady if and only if the Green Lord is with the Yellow Lady

3. The Red Lord is with the Blue Lady, if and only if the Green Lord is with the Red Lady.

There is a unique solution to this problem, when all the statements
are satisfied! However, all double implications need to be satisfied,
which happens only when all are taken as false.

LORDS    LADIES
---------------
Yellow | Green
Green  | Blue
Red    | Yellow
Blue   | Red

Posted by dhruv on 2004-08-22 13:21:39