document.write( "Question 1200086: Five fair coins were tossed simultaneously. What is the probability of getting three heads and two tails?
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document.write( "A. 1/32
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document.write( "B. 1/16
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document.write( "C. 1/8
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document.write( "D. 1/4 \n" );
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Algebra.Com's Answer #834113 by greenestamps(13200)![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "The wording of the problem most definitely does NOT say the 5 outcomes are 3 heads followed by 2 tails in that order.... \n" ); document.write( "The number of possible outcomes on 5 flips of the coin is 2^5 = 32. \n" ); document.write( "The number of ways (different orders) of getting 3 heads and 2 tails is the number of different ways of arranging the letters HHHTT. By a well-known counting principle, that number of ways is \n" ); document.write( "So the probability of getting 3 heads and 2 tails is 10/32 = 5/16. \n" ); document.write( "Note for problems involving flipping fair coins, a familiarity with Pascal's Triangle is helpful. The 5th row of Pascal's Triangle is \n" ); document.write( "1 5 10 10 5 1 \n" ); document.write( "Those numbers represent, respectively, the numbers of different ways of getting 5, 4, 3, 2, 1, or 0 heads. \n" ); document.write( " \n" ); document.write( " |