4 persons r selected at random out of 3 men , 2 women, and 4 children. The probability that there r exactly 2 children in the selection is..???
206First list out all the possibilities........
For total no. of events
and for no. of possible events
If you know Permutations and Combinations, this can be done quickly.
269i think it shud be done in this way...
first, total probability=9C4
since there should be exactly 2 children,so for them...we have,4C2
now,from rest of the 5 people we need two select 2 more people,i.e.5C2.....
therefore,finally we have
4C2 x 5C2
------------ =1021
9C4
that's wat i got....
206and that is absolutely right!! :)
Astha Gupta ...:)