December 6, 2011

Problem of the Week

for Tuesday, December 6, 2011

You are given 9 different unmarked weights and a three-pan balance scale. You can place one weight on each of the three pans of the scale, and the scale will then indicate which of the three is the heaviest and which of the three is the lightest. What is the smallest number of weighings that is guaranteed to allow you to determine the three heaviest weights in the correct order? Describe your procedure.

Winners of the three-balance problem