#Find number of ways.

12 messages · Page 1 of 1 (latest)

whole wrenBOT
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deep pike
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So the answer is apparently 8 for this question

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i tried to solve this question intuitively and according to me there is no way P_(n+1)-P_n = 15 for n=8

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so what i did was start with n= 5(since this is the lowest number where you can select people non-consecutively)

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and found that there is only one way to select 3 people

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similarly for n=6there is 3 ways

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n=7 6 ways

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n=8 10 ways

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and it goes on so forth as(starting from n=5)

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1,3,6,10,15,21,28.....

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and as you can see it simply isnt possible for P_(n+1)-P_n= 15 for n=8