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Stay in Balance


blocks on teeter totter

Credit: Getty Images

Two players, each with a collection of weights, sit in front of a plank that weighs three kilograms with two supports at −1 and +1. Each player wants to get rid of his or her weights, by placing them on integral markers, at most one weight per integral marker. So, for example, player A may not place a weight above A's weights or player B's weights. Further, neither player is allowed to place a weight at −1, 0, or +1.

In a turn, a player must put at least one weight somewhere on the plank, but may put several weights on the plank, if they are at consecutive integer marks. The goal of each player is to be the first to place all of his or her weights without causing the plank to tip (by having a strictly negative torque on the right support or a strictly positive torque on the left support).


 

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