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probability

by winnerhere » Sun May 17, 2009 10:12 pm
From a group of 30 persons, 2 are to be selected. The first one to be a picked shall be sent to Mumbai and the other are to Kolkota. What is the probability of Gautam going to Kolkota.

(a) 2/30 C2 (b) 1/30C2 (c ) 1/30P2 (d) can not be determined
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by scoobydooby » Sun May 17, 2009 10:18 pm
2 out of 30 people can be selected in 30C2 ways.
only 1 way of selecting gautam, only way 1 way of selecting gautam second=only one way of going to kolkata.
so probability of gautam going to kolkata: 1*1/30C2

hence, B
Last edited by scoobydooby on Sun May 17, 2009 10:42 pm, edited 1 time in total.
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by winnerhere » Sun May 17, 2009 10:32 pm
scoobydooby wrote:2 out of 30 people can be selected in 30C2 ways.
only 1 way of selecting gautam, only way 1 way of gautam going to kolkata.
so probability of gautam going to kolkata: 1*1/30C2

hence, B
brother..what confused me is goutham shouldnot be selected first and should be selected only second...so i was thinking about conditional probability and all.

i mean among the different permutations,the permutations which has goutham as the second option etc..

it was so confusing.I am thinking too much at times :oops:
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by Uri » Mon May 18, 2009 1:06 am
2 can be selected from 30 in 30C2 ways.
if gautam has to be selected for only kolkata, then he can occupy this place in only 1 way.
so, probability of gautam going to kolkata = 1/ 30C2
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