document.write( "Question 917652: 1. The Knick play the Bulls in a seven game series that end when one team has won four games. We record the outcome of a game with a W for a Knick win and an L for a Knick loss.\r
\n" ); document.write( "\n" ); document.write( "How many series would have to be played to be sure that the same outcome happens twice?\r
\n" ); document.write( "\n" ); document.write( "I know there are a total of 840 possible outcomes from a permutation of (7,4), so would it just be 840 divided by 2?
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Algebra.Com's Answer #556757 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
You have seven games. There are 2 outcomes for each game.\r
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\n" ); document.write( "\n" ); document.write( "There are 2^7 = 128 ways to have a Ws and Ls in a seven character sequence; however, you cannot have something like WWWWWLL because once you get that 4th W, the series is over. So in reality, you the upper limit on Ws is 4. The same is said for the L's as well.\r
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\n" ); document.write( "\n" ); document.write( "So here is a list of all the possible outcomes. \r
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\n" ); document.write( "\n" ); document.write( "For example, scenario #3 has \"LLLWWL\" under the \"Game Sequence\" column. This means we have the Knicks lose 3 times in a row (L, L, L). The next game has the Knicks winning (W). The Knicks win again in game 5 (W). However, the Knicks lose (L) game 6. Overall, they lose the championship series because the opponent has gained 4 wins before them. This is what I mean by \"Knicks lose\" in the \"Championship Summary\" column.\r
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\n" ); document.write( "\n" ); document.write( "The other rows are read in a similar way. Let me know if you have any questions on that.\r
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\n" ); document.write( "\n" ); document.write( "There are 70 possible outcomes.\r
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NumberGame SequenceChampionship Summary
1LLLL4 game series, Knicks lose
2LLLWL5 game series, Knicks lose
3LLLWWL6 game series, Knicks lose
4LLLWWWL7 game series, Knicks lose
5LLLWWWW7 game series, Knicks win
6LLWLL5 game series, Knicks lose
7LLWLWL6 game series, Knicks lose
8LLWLWWL7 game series, Knicks lose
9LLWLWWW7 game series, Knicks win
10LLWWLL6 game series, Knicks lose
11LLWWLWL7 game series, Knicks lose
12LLWWLWW7 game series, Knicks win
13LLWWWLL7 game series, Knicks lose
14LLWWWLW7 game series, Knicks win
15LLWWWW6 game series, Knicks win
16LWLLL5 game series, Knicks lose
17LWLLWL6 game series, Knicks lose
18LWLLWWL7 game series, Knicks lose
19LWLLWWW7 game series, Knicks win
20LWLWLL6 game series, Knicks lose
21LWLWLWL7 game series, Knicks lose
22LWLWLWW7 game series, Knicks win
23LWLWWLL7 game series, Knicks lose
24LWLWWLW7 game series, Knicks win
25LWLWWW6 game series, Knicks win
26LWWLLL6 game series, Knicks lose
27LWWLLWL7 game series, Knicks lose
28LWWLLWW7 game series, Knicks win
29LWWLWLL7 game series, Knicks lose
30LWWLWLW7 game series, Knicks win
31LWWLWW6 game series, Knicks win
32LWWWLLL7 game series, Knicks lose
33LWWWLLW7 game series, Knicks win
34LWWWLW6 game series, Knicks win
35LWWWW5 game series, Knicks win
36WLLLL5 game series, Knicks lose
37WLLLWL6 game series, Knicks lose
38WLLLWWL7 game series, Knicks lose
39WLLLWWW7 game series, Knicks win
40WLLWLL6 game series, Knicks lose
41WLLWLWL7 game series, Knicks lose
42WLLWLWW7 game series, Knicks win
43WLLWWLL7 game series, Knicks lose
44WLLWWLW7 game series, Knicks win
45WLLWWW6 game series, Knicks win
46WLWLLL6 game series, Knicks lose
47WLWLLWL7 game series, Knicks lose
48WLWLLWW7 game series, Knicks win
49WLWLWLL7 game series, Knicks lose
50WLWLWLW7 game series, Knicks win
51WLWLWW6 game series, Knicks win
52WLWWLLL7 game series, Knicks lose
53WLWWLLW7 game series, Knicks win
54WLWWLW6 game series, Knicks win
55WLWWW5 game series, Knicks win
56WWLLLL6 game series, Knicks lose
57WWLLLWL7 game series, Knicks lose
58WWLLLWW7 game series, Knicks win
59WWLLWLL7 game series, Knicks lose
60WWLLWLW7 game series, Knicks win
61WWLLWW6 game series, Knicks win
62WWLWLLL7 game series, Knicks lose
63WWLWLLW7 game series, Knicks win
64WWLWLW6 game series, Knicks win
65WWLWW5 game series, Knicks win
66WWWLLLL7 game series, Knicks lose
67WWWLLLW7 game series, Knicks win
68WWWLLW6 game series, Knicks win
69WWWLW5 game series, Knicks win
70WWWW4 game series, Knicks win
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\n" ); document.write( "\n" ); document.write( "Again there are 70 possible outcomes. The other 128-70 = 58 outcomes are not possible. This would be something like WWWWWLL (5 W's aren't possible).\r
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\n" ); document.write( "\n" ); document.write( "I didn't use a formula. I simply listed out all of the possible outcomes (all 128) using this combinatorics calculator. Then I picked out the outcomes that weren't possible.\r
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\n" ); document.write( "\n" ); document.write( "So this means that 71 series would have to be played to make sure the same outcome happens twice. They need to play 70 series to generate all of the outcomes. That 71st game will be a repeat of one of the 70 already listed.\r
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