1. The famous British spy 001 has to choose one of four routes, a, b, c, or d (listed in order of speed in good conditions) to ski down a mountain. Fast routes are more likely to be struck by an avalanche. At the same time, the notorious rival spy 002 has to choose whether to use (y) or not to use (x) his valuable explosive device to cause an avalanche. The payoffs of this game are represented here.