There are six boxes containing 5, 7, 14, 16, 18, 29 balls of either red or blue in colour. Some boxes contain only red balls and others contain only blue.

One sales man sold one box out of them and then he says, "I have the same number of red and blue balls left over."

Which box is sold out?

The box of 29 balls is sold, leaving 5, 7, and 18 of one color and 14 and 16 of the other. No other groupings from five boxes splits evenly.

Posted by Bryan on 2003-08-14 14:28:27