Help: probability question ?

[superiorus]

I develop a Bitcoin related project.
I need help to solve a math problem:

I have 10 boxes.
8 boxes are not identical and 2 boxes are identical.
What are the chances to find the 2 identical boxes (only 2 picks allowed)?
There is a formula to hep me?
How to calculate?

Thank you

[1715283228]

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[1715283228]

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[Lutpin]

I have 10 boxes.
8 boxes are not identical and 2 boxes are identical.
What are the chances to find the 2 identical boxes (only 2 picks allowed)?

The chance for the first one is 2/10, the chance for the second one is 1/9, hence the total chance is 2/10*1/9= 0.0222 (or 2.22%).

[KenR]

This is not a probability question.There is topic called Permutations and Combinations in Algebra to solve this problems which are fairly easy to. Problems like "8 balls of red color and 9 balls of blue color should be arranged in 10 boxes,how many ways we can arrange them" follow into this categories.I can help you with the problem,just leave me a PM .In case you want to solve it on your own the formula's http://www.indiabix.com/aptitude/permutation-and-combination/formulas

[BitcoinBlackjack]

I have 10 boxes.
8 boxes are not identical and 2 boxes are identical.
What are the chances to find the 2 identical boxes (only 2 picks allowed)?

The chance for the first one is 2/10, the chance for the second one is 1/9, hence the total chance is 2/10*1/9= 0.0222 (or 2.22%).

This sounds about right!

[knightkon]

This is not a probability question.There is topic called Permutations and Combinations in Algebra to solve this problems which are fairly easy to. Problems like "8 balls of red color and 9 balls of blue color should be arranged in 10 boxes,how many ways we can arrange them" follow into this categories.I can help you with the problem,just leave me a PM .In case you want to solve it on your own the formula's http://www.indiabix.com/aptitude/permutation-and-combination/formulas

This is not a probability question: this is a question on your school work and you are looking for an answer.  I hope that you understand why the answer is what it is so that next time you will be able to use this to advance yourself.  If you do not, then you were better not knowing at all.