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Difficult Math Problem #78 - Probability

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Difficult Math Problem #78 - Probability

by 800guy » Wed Dec 20, 2006 8:51 am
A rental car service facility has 10 foreign cars and 15 domestic cars waiting to be serviced on a particular Saturday morning. Because there are so few mechanics, only 6 can be serviced.

(a) If the 6 cars are chosen at random, what is the probability that 3 of the cars selected
are domestic and the other 3 are foreign?
(b) If the 6 cars are chosen at random, what is the probability that at most one domestic
car is selected?
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by 800guy » Sun Dec 31, 2006 12:26 pm
OA coming when a few people reply
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by maxim730 » Tue Jan 02, 2007 11:11 am
A) (10C3*15C3) / (25C6)

B) (15C6)/ (25C6)

Shrug..:(
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OA

by 800guy » Wed Jan 03, 2007 11:53 am
OA

A) 10C3*15C3/25C6
B) Probability of no domestic car + Probability of 1 domestic car =
10C6/25C6 + 15C1 *10C5/25C6
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