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Thu 23 May, 2013 12:40 pm
Lets assume we have an urn with 20,000 numbers (1-20,000). Lets have 40 drawings of 20 numbers when after each drawing numbers are recorded and returned to urn.
How do I calculate the probability that no number will be drawn twice, 1 number will be drawn twice, 2 numbers will be drawn twice etc.
In other words what is the probability for a number to be drawn twice under such circumstances?
Thank you in advance for your help
zoran
@zbrkanac,
Exactly twice or more than once?
@zbrkanac,
For the no number drawn more than once case:
C(20000,20)*C(19980,20)*C(19960,20)*...*C(19220,20)/C(20000,20)^40
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