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tino
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If we want a chance of 5% or less that a person will 28 Apr 2003, 11:20
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If we want a chance of 5% or less that a person will encounter any question twice (in first and second test) in two consequtive random selections of 40 questions out of a question bank, how large should this question bank be?

I fear you need Excel to solve this one.



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If we want a chance of 5% or less that a person will 05 May 2003, 00:05
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x is the number of questions in the bank. The probability of having at least one question in two selections of 40 = 1 - [(x-40)C40/xC40]

It should be less than or equal to 0.05.

1 - [(x-40)C40/xC40]<=0.05

Excel says that x should be about 31000. P=0.0503.
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If we want a chance of 5% or less that a person will 06 May 2003, 04:26
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thanks :)

Right now we have capacity of 4 questions a day, which means developing such a bank will take 21 years.

Ok, this means we need software that would remember which questions you already answered...
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If we want a chance of 5% or less that a person will 06 May 2003, 05:05
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The number of questions in your bank should increse exponentially. In this case it should take much less time. :D
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If we want a chance of 5% or less that a person will 06 May 2003, 05:35
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Great idea, stolyar!

If bb got $1 mln, we could launch a campaign - get $10 for every question you prepared, + $1 for each question your friends prepared, so that people could use a multi-level marketing, to get an exponent :)
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If we want a chance of 5% or less that a person will 10 May 2003, 20:54
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Great idea, stolyar!

If bb got $1 mln, we could launch a campaign - get $10 for every question you prepared, + $1 for each question your friends prepared, so that people could use a multi-level marketing, to get an exponent :)
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Great Idea. I really love it... can we drop the second part and leave me with $1 mln?



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