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Probability of independent events

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by determined » Sun Nov 01, 2009 7:42 pm
Probability that student A can solve the problem=1/3
Probability that student B can solve the problem=1/5
Probability that only one of them can solve the problem=?

How would you solve this problem? I thought since they are independent events,

p(AUB)= p(A)+P(B)-p(A and B)= 1/3+1/5-1/3.1/5= 7/15

but if you try to solve it as

p(A).(1-p(B))+ p(B).(1-p(B))= 1/3.4/5 + 2/3.1/5 = 6/15

Which one is correct??
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Source: — Problem Solving |

Re: Probability of independent events

by ayushr » Sun Nov 01, 2009 9:18 pm
determined wrote:
p(AUB)= p(A)+P(B)-p(A and B)= 1/3+1/5-1/3.1/5= 7/15
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by determined » Sun Nov 01, 2009 11:48 pm
Thanks very much!!!
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by beatthegmat » Mon Nov 02, 2009 10:42 am
Moving post to problem solving forum.
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