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earth@work
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 Posted: Wed Oct 08, 2008 5:01 pm Post subject: probability |
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| In a lottery, a person choses six different natural numbers at random from 1 to 20, and if these six numbers match with the six numbers already fixed by the lottery committee, he wins the prize. What is the probability of Winning the prize in the game. |
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earth@work
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| Posted: Thu Oct 09, 2008 9:53 am Post subject: |
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| pls help.... answer is 1/38760 |
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mental
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| Posted: Thu Oct 09, 2008 10:14 am Post subject: |
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just think it slighly different manner
how many ways can 6 numbers be chosen out of 20 numbers
they are not asking arrangements
20c6 = 20!/14!*6! = solve it you get 38760
one combination is selected out of it by selectors
probability = 1/38760 |
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earth@work
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| Posted: Thu Oct 09, 2008 10:30 am Post subject: |
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| thanks a lot! |
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4meonly
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| Posted: Sat Oct 11, 2008 12:32 am Post subject: |
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I doubt whether this Q is correct
4me, the probability will be
1/20 * 1/19 * 1/18 * 1/17 * 1/16 * 1/15 we'll get less then 1/38760
Because 123456 is not the same as 654321
answer 1/38760 assumens that order is not important but it should be important!!! |
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mental
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| Posted: Sat Oct 11, 2008 7:41 am Post subject: Re: probability |
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| earth@work wrote: | | In a lottery, a person choses six different natural numbers at random from 1 to 20, and if these six numbers match with the six numbers already fixed by the lottery committee, he wins the prize. What is the probability of Winning the prize in the game. |
the quaestion is not talking about arrangements
also just think that it has double digit numbers
20, 19, 8, 7 are actually only four numbers, but if we write in one go....201987...can also mean...2,0,1,9,8,7...6 different numbers!!!!
neways thats im-material |
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canuckclint
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| Posted: Sat Oct 11, 2008 9:25 am Post subject: |
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| 4meonly wrote: | I doubt whether this Q is correct
4me, the probability will be
1/20 * 1/19 * 1/18 * 1/17 * 1/16 * 1/15 we'll get less then 1/38760
Because 123456 is not the same as 654321
answer 1/38760 assumens that order is not important but it should be important!!! |
This does take into account order. Since the first number is 1/20 chance and so on.
Its just the probability happens to be the same if they are switched.
For example. what is the probability of coin toss:
TTH or HTT are the same 1/8
Makes sense? |
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