Difference between revisions of "2011 AIME II Problems/Problem 12"
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Nine delegates, three each from three different countries, randomly select chairs at a round table that seats nine people. Let the probability that each delegate sits next to at least one delegate from another country be m/n where m and n are relatively prime positive integers. Find m+n. | Nine delegates, three each from three different countries, randomly select chairs at a round table that seats nine people. Let the probability that each delegate sits next to at least one delegate from another country be m/n where m and n are relatively prime positive integers. Find m+n. | ||
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| + | Solution: | ||
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| + | Use complementary probability and PIE. | ||
Revision as of 18:39, 31 March 2011
Problem:
Nine delegates, three each from three different countries, randomly select chairs at a round table that seats nine people. Let the probability that each delegate sits next to at least one delegate from another country be m/n where m and n are relatively prime positive integers. Find m+n.
Solution:
Use complementary probability and PIE.
