Problem #6160 Two roads, Broadway and State, connect the towns of East-land and Harping. Three roads, Park, Fairvew, and Main, connect the towns of Harping and Johnstown. Find the number of possible routs from East-land to Johnstown that pass through Harping. Then find the probability that State and Fairvew will be used if a rout is selected at random. State the probability as a fraction and percent and its likelihood.
Solution Due to combinatorial rule of product: “ if we have ways of doing something and ways of doing another thing, then there are ways of performing both actions” the number of possible routs from East-land to Johnstown is . Thus, the probability of choosing any route(under the assumption of selecting at random, that is with equal probabilities) is . Hence, the probability that our route is State—Fairvew is as any other of the possible ways.
Note, that the probability that one will use State is , and the probability that one will use Fairvew is .
Answer or or or .
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