find the expected number of boys in a family of 6 children.?
594326
50/50 chance it will be a boy for each birth therefore three boys
868097
-\naside from 1,\n2,3,4,6,12
631878
If you are only concerned about the ways that you can place the 15 women between the 10 men, then you have 9 positions to place the 15 women.  (You don't have to worry about the arrangements for the men since there has to be one in between there is only one way to arrange.) These are the ways to do it (regardless of order).\n\na) 1 1 1 1 1 1 1 1 7\nb) 1 1 1 1 1 1 1 2 6\nc) 1 1 1 1 1 1 1 3 5\nd) 1 1 1 1 1 1 1 4 4\ne) 1 1 1 1 1 1 2 2 5\nf) 1 1 1 1 1 1 2 3 4\ng) 1 1 1 1 1 1 3 3 3\nh) 1 1 1 1 1 2 2 2 4\ni) 1 1 1 1 1 2 2 3 3\nj) 1 1 1 1 2 2 2 2 3\nk) 1 1 1 2 2 2 2 2 2\n\nNow to rearrange these, you would have to use the multinomial coefficient.  You have to use this because you have repeats: For example in a), you can switch two 1's around and get the same result, but moving the 7 will give you a different result.\n\nFor a), there are 9!/8!1! = 9 ways to arrange.\nFor b) and c), there are 9!/7!1!1! = 72 ways to arrange.\nFor d), 9!/7!2! = 36 ways.\nFor e), 9!/6!2!1! = 252 ways.\nFor f), 9!/6!1!1!1! = 504 ways.\nFor g), 9!/6!3! = 84 ways.\nFor h), 9!/5!3!1! = 504 ways.\nFor i), 9!/5!2!2! = 756 ways.\nFor j), 9!/4!4!1! = 630 ways.\nFor k), 9!/3!6! = 84 ways.\n\nSo in total, there are 9 + 72 + 72 + 36 + 252 + 504 + 504 + 84 + 756 + 630 + 84 = 3003 ways to place the 15 women between the 10 men.\n\nNow if after that you want to know how many ways there are to arrange if you do make a difference between men and between women, then multiply by the number of ways to arrange the men and women.\n\n3003*10!*15! = 14,250,102,106,034,995,200,000 ways.\n\nNotice this is less than the number of ways to arrange all 25 people regardless of gender.  That would have been 25! = 15,511,210,043,330,985,984,000,000.
718258
May be you should ask it in two questions.\n\nHow many brothers and sisters in your family?\n\nAnd you are number?
731902
There are 20 students in the class. There are 4 possibilities when you choose the 3 random students. I've included the probabilities of these 4 possibilities. 1) and 3) are the answers to your questions.\n\n1)   3 boys = (4/20)(3/19)(2/18) = 0.0035\n\n2)    2 b, 1 g = (4/20)(3/19)(16/18)x3(=3C2) = 0.0842\n\n3)    2 g, 1 b = (16/20)(15/19)(4/18)x3(=3C2) = 0.4211\n\n4)     3 g = (16/20)(15/19)(14/18) =  0.4912\n\nFor the probabilities to be correct they must sum to 1:\n\n0.0035+0.0842+0.4211+0.4912 = 1
753093
My brothers x was one of 14 children. imagine if 10 of them would have 2-3 kids a piece and so on
153320
27 boys - 21 noncity boys = 6 city boys.\n18 city males - 6 city boys = 12 city men.\n27 men - 12 city men = 15 noncity men.\n\n15 noncity men + 21 noncity boys + 21 noncity females = 57 noncity people.\n\n57 noncity people + 42 city people = 99 people.
873766
Lots of choices:\n6 boys and 21 girls\n9 boys and 18 girls\n12 boys and 15 girls\n15 boys and 12 girls\n18 boys and 9 girls\n21 boys and 6 girls\n\nWithout another piece of information (such as there are 3 more girls than boys, or twice as many boys as girls) there is no way to get a unique answer.
233027
There are 8! different arrangements (permutations) of the 8 friends.\n\nThere are 4! different arrangements of the 4 boys.\n\nThere are 5 different locations where the leftmost boy can sit when the 4 boys sit together.\n\nTherefore, there are 5*4! (or 5!) arrangements of the boys where all the boys sit together.  But there are also 4! arrangements of the 4 girls in the remaining slots.  So there are 5!*4! arrangements where the 4 boys sit together.\n\nSince there are 8! arrangements overall, the probability of all boys sitting together is (5!*4!)/8!.\n\nSimilarly, if the boys sit to the left and the girls sit to the right, then the probability is (4!*4!)/8!.\n\nInterestingly, this last answer is also the same probability as boy-girl-boy-girl-boy-girl-boy-girl and also the probability of girl-boy-girl-boy-girl-boy-girl-boy.  Therefore, the probability of alternating seats is (2*4!*4!)/8!.\n\nRecall that n! (read n-factorial) is n*(n-1)*(n-2)*...*3*2*1.
227352
About two million.\n\n(600,000 males above 18 plus women and children.)
389689
You need to know the total number of boys.\nThen take 4 divided by the total number of boys.\nThis will give you the probability.\nMultiply by 100 to get the percent.
134173
a population of 12 people?
181855
If 2/5 of the students are boys, 3/5 must be girls.\nTherefore the boy to girl ratio is (2/5):(3/5)=2:3.
806831
All your responders so far have assumed that the next child's gender is independent of the prior children's genders. That is a correct assumption.\n\nThey have also assumed that the probability of having a boy is 50%. This is not quite true. Population-wide, the ratio of baby boys to baby girls is approximately 105 to 100, so the percentage is actually a bit over 51%. \n\nThis is also based on the assumption that the probabilities do not vary from one couple to another. You may have read descriptions of techniques for increasing the probability of having a girl, or of having a boy. And if so, you know that the things you have to do (I won't get too graphic here) are things that some couples are likely to be doing already (because of the geometry of their bodies, or the chemistry of their bodies, or because of their technique). So I suspect (and this is only my opinion) that the probability of having a child of one gender or the other varies from couple to couple.\n\nThat last-mentioned suspicion could probably be tested by determining the relative frequency of families with different combinations of boys and girls. Do siblings of the same sex tend to occur more frequently than if each birth were a 51/49 proposition? If so, then there is likely a variation from couple to couple. And if they occur LESS frequently, then we REALLY have a conundrum, and I have NO idea what it would mean.
736169
i have 6 kids....what do you think?
192695
You have the following lists:\nB B B\nB B G\nB G B\nG B B\nB G G\nG B G\nG G B\nG G G\n\nSo you have 8 variations and of those 3 are 2 boys 1 girl so the probability is 3/8.
842155
5 in girls\n6 in boys