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.

Hypothesis: Yellow lord is with the red lady.  Can this be true?

The green lord would not be with the red lady and the red lord would not be with the blue lady.  (clue #3).

Additionally, we know by this point that the yellow lord would not be with the blue or green ladies and that neither the blue or green lords are with the red lady unless she is a swinger.

From clue #2, we know that the green lord would be with the yellow lady, forcing the red and blue lords to both fight over the green lady, leaving the blue lady crying as her date stands her up.

Strike hypothesis as FALSE.

FACT: The yellow lord is NOT WITH the red lady.  This means the green lord is NOT WITH the red lady (clue #1).  This leaves the blue lord with the red lady.

Since the green lord is not with the red lady, we know that the red lord is not with the blue lady (clue #3).

Since the green lord is not with the red lady, the yellow lord is not with the blue lady (clue #1).  Thus, the yellow lord is with the green lady.

Since the green lady is with yellow, she is not with the red lord.  This indicates the red lord is with the yellow lady.  Therefore, the green lord must be with the blue lady.

So in nine months, assuming each couple has 1 kid, we'll have 1 orange kid, 1 purple kid, and 2 greenish kids (1 slightly yellow and 1 slightly blue).

Fun puzzle.

Posted by mrcqm on 2004-06-14 23:53:22