They asked a puzzle question to test problem solving skills. It was a riddle about finding the heaviest ball in a group of seven, where 6 all weighed the same and only one weighed a different amount. The trick was to weigh it using a simple two tray scale, and use the minimum amount of weighs. I think this question is in the movie Die Hard, actually.
I can't remember, I think I did it in 3 moves.
You can do it in 2. First put 3 balls on each side. If the scale is balanced, the heavy ball is the 7th one, which was not weighed. If one side is heavier, remove all balls from the scale. Weigh 2 of the 3 balls from the heavy side, 1 on each side. If they are balanced, the heavy ball is the 3rd ball.
Dec 15, 2013