Probability question

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Probability question

by mgmt_gmat » Fri Feb 12, 2010 1:24 am
The membership of a committee consists of 3 English teachers, 4
Mathematics teachers, and 2 Social Studies teachers. If 2
committee members are to be selected at random to write the
committee's report, what is the probability that the two members
selected will both be English teachers?
A. 2/3
B. 1/3
C. 2/9
D. 1/12
E. 1/24
Source: — Problem Solving |

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by sanju09 » Fri Feb 12, 2010 1:41 am
mgmt_gmat wrote:The membership of a committee consists of 3 English teachers, 4
Mathematics teachers, and 2 Social Studies teachers. If 2
committee members are to be selected at random to write the
committee's report, what is the probability that the two members
selected will both be English teachers?
A. 2/3
B. 1/3
C. 2/9
D. 1/12
E. 1/24
There are only 3 English teachers in a total of 9 teachers. Any 2 teachers can be chosen in 9C2 = 36 ways, and the favorable ways for them to be English teachers are 3C2 = 3, and hence the probability = 3/36 = 1/12.

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