document.write( "Question 917936: The Red Sox play the Yankees in a seven game series that ends when one team has won four games.
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document.write( "We record the outcome of a game with a W for a Red Sox win and an L for a Red Sox loss, e.g.
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document.write( "WWWW, WLWLWLW, or WWLLLWW.
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document.write( "i. How many possible outcomes are there?
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document.write( "ii. How many series would have to be played to be sure that the same outcome happens twice?
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document.write( "iii. If the Red Sox win in four games with a total of 17 runs, how many ways could their runs be
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document.write( "distributed among the four games? (Sample run distributions: (2, 7, 5, 3) (12, 1, 1, 3))
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Algebra.Com's Answer #556844 by richard1234(7193)![]() ![]() You can put this solution on YOUR website! i. Casework on # games played (we only count # outcomes with 4 W's)\r \n" ); document.write( "\n" ); document.write( "4 games: Only WWWW, 1 outcome \n" ); document.write( "5 games: Any rearrangement of WWWWL with the last game W, 4C1 = 4 outcomes \n" ); document.write( "6 games: Any rearrangement of WWWWLL, with the last game W, 5C2 = 10 outcomes \n" ); document.write( "7 games: Any rearrangement of WWWWLLL, with the last game W, 6C3 = 20 outcomes\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1+4+10+20 = 35. Multiply by 2 to account for outcomes with 4 L's --> 70 different outcomes\r \n" ); document.write( "\n" ); document.write( "ii. 71 by Pigeonhole\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "iii. Equivalent to the number of 4-tuples whose sum is 17 and each element is at least 1 (since it is impossible to win with 0 runs). This is equal to (13+3)C3 = 16C3 = 560 (look up stars and bars if you're not familiar) \n" ); document.write( " |