<PRE><B>Question 752817</B>
 (a) A class has 10 boys and 5 girls. Three students are selected at random one after another. 
Find the probability that (i) first two are boys and third is girl 
P(bbg) = (10/15)(9/14)(5/13)
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(ii) first and third are of same sex and the second is of opposite sex.
P(bgb) + P(gbg) = (10/15)(5/14)(9/13) + (5/15)(10/14)(4/13)

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cheers,
Stan H.
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