[CameronMichael]

40% are male and 60% are female. What is the probability of the next 2 random people selected are the same gender ?

[ebaines]

Suppose the question was "what's the probabiliy that 2 random people selected are both male" - would you be able to answer that? Or how about the probability of both being female? If you can answer these two questions then the probability of both being of the same gender is equal to the probability that both are male plus the probability that both are female. Hope this helps.

[CameronMichael]

Oh right! :p thanks it does help :-) but it also says "" 2/5 are male and 3/5 are female, assuming 40% are male and 60% female what is the probability that the next 2 people selected are the same gender"" I don't know if that makes any difference for you, thanks.

If we can assume that the 40%/60% split doesn't vary between the first and second pick then it's easy. But if the problem said that there was a finite number of peopkle - say, 10 - and that after you pick one person the second person must be picked from one of the remaoning 9 it gets a little trickier. For example, in an infintely large population the probability of picking a male on both the first and second picks is 0.4^2, or 0.16. But if there are only ten people to chose from, and we chose without replacement (meaning the same person cannot be picked twice) then the probability of picking two males is (4/10)x(3/9) = 0.133. For your problem since they do not mention population size nor whether the sme person may be picked twice I would ignore this complication and simply use 0.4^2.

[CameronMichael]

Thank-you :) that helps a lot!! :)