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A study of the strengths of Ivy League football teams

shows that if a school has a strong team one year it is equally likely to have a strong team or average team next year; if it has an average team, half the time it is average next year, and if it changes it is just as likely to become strong as weak; if it is weak it has 2/3 probability of remaining so and 1/3 of becoming average.

• A school has a strong team. On the average, how long will it be before it has another strong team?
• A school has a weak team; how long (on the average) must the alumni wait for a strong team?