1985 AHSME Problems/Problem 6
Problem
One student in a class of boys and girls is chosen to represent the class. Each student is equally likely to be chosen and the probability that a boy is chosen is of the probability that a girl is chosen. The ratio of the number of boys to the total number of boys and girls is
Solution
Let the probability that a boy is chosen be . Since the sum of the probability that a boy is chosen and a girl is chosen is , we have the probability that a girl is chosen is . We know that of this is , so .
Notice that . But we already know that this is , so that is our final answer, .
See Also
1985 AHSME (Problems • Answer Key • Resources) | ||
Preceded by Problem 5 |
Followed by Problem 7 | |
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