You are given a two sided scale and you are given 8 basketballs that all weigh equal except for one ball that weighs a little more than any of the other balls. What would you do in order to find the heavier ball in only 2 weighings?
Group the balls into one with 2 balls and one with 6 balls.
1. Divide the group of 6 into 2 halves and put each half on the scale.
a. If one of the sides sinks lower, then that group has the heavier ball otherwise go to step b. Split the group of 3 balls into one with 1 ball and one with 2 balls. Place the 2 balls on the scale, if one side sinks lower that is the side that has the heavier ball.
b. Since the group of 6 did not have the ball we move to the group of 2 balls. Place both balls on different sides of scales the side that sinks lower is the side with the heavier ball.