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Prob

by ssraf » Fri Jun 13, 2008 10:33 pm
Jo and Jose work at an auto repair centre with 4 other workers. For a survey on healthcare insurance 2 to workers will randomly be interviewed. What is the probability both Jo and Jose will be chosen?
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by babachal » Fri Jun 13, 2008 11:33 pm
whole people 6
Jo's randomly chosen probability is 1/6
Jose's randomly probability is 1/6

their both probabilty is (1/6)*(1/6)=1/36
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by Ian Stewart » Sat Jun 14, 2008 2:01 am
The probability the first person chosen is either Jo or Jose is 2/6. Then, the probability the other one is chosen next is 1/5 (there are 5 people left, and only one of them gives you the result you want). So (2/6)*(1/5) = 1/15.

Or you can look at it this way: there are 6C2 different pairs of people that could be chosen. One of these pairs is Jo and Jose. So the probability must be 1/6C2, from the definition of probability. 1/6C2 = 1/15.
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