Pick A Sib-set Boy-girl Twins

In how many ways can 4 boys and 3 girls arranged in a row if no two girls are together?

Hey there,We have 4 boys and 3 girls arranged in a row such that no two girls are adjacent.I would first start off with arranging/seating the boys . 4 boys can be seated in [math]4! [/math]ways. Thus 4 boys can be seated in [math]4!= 4*3*2*1= 24[/math] ways.{Note: Order matters here. i.e. Seating arrangement of B1 B2 B3 B4 is different from B1 B3 B2 B4, where, B1,B2,B3,B4 are four different boys.}So, this is a permutation and so 4 boys can be arranged in 4 places in [math]4P4[/math] ways= [math]\dfrac{4!}{(4-4)!}=\dfrac{4!}{0!} =24.[/math] Thus the boys can be arranged in 4! = 24 ways. {Note: [math]0!=1[/math]}Now we have to place/arrange the girls such that no two girls are adjacent. So we can arrange them in 5 different places as shown below._B_B_B_B_The first girl can be seated in any of the [math]5[/math] places.The second girl can be seated in any of the remaining [math]4[/math] places.The third girl can be seated in any of the remaining [math]3[/math] places.So, the number of ways that the girls can be seated: [math]5*4*3=60[/math]This can also be done as follows: There are 5 places available for 3 girls to be seated and the order of seating matters. Thus the 3 girls can be seated in 5 places in [math]5P3[/math] ways = [math]\dfrac{5!}{(5-3)!}=\dfrac{5!}{2!}=60[/math]The total number of ways that 4 boys and 3 girls can be arranged in a row such that no two girls are adjacent : [math]4P4 * 5P3 = 24*60 = 1440[/math] ways.

Is it possible for a baby to have two biological fathers?

The entire idea is utterly absurd. I’d be laughed at and scorned if other people heard.But, just the same, there are a very few people having DNA from three parents.[1]If you are technically minded, the procedure involves transferring the nucleus from one unfertilized egg (with normal nuclear DNA but having faulty mitochondrial DNA) into another unfertilized egg (having normal mitochondrial DNA which had its nucleus removed) and then fertilizing that egg (containing genetic material from two mothers) in vitro.transferring mitochondria from a third person into a newly fertilized egg. That makes sense in situations where the mother carries a defect in her mitochondrial DNA that might cause a disease in her children. It’s been legal in the UK in 2015 but, insofar as I know, no other country permits it.This child actually has two mothers and one father. In principle, the procedure could be altered so that it had two fathers but that would be hard.Very controversial.Researchers sometimes create mice having four parents, tetraparental mice. To do that, they combine two embryos.[2] Each individual cell has two parents but the overall animal has some cells from each embryo.Typically, the experimenters use embryos that should produce different coat colors so that it is easier to see which part of the skin came from which parent.This procedure may be technically possible in people but there doesn’t seem to be any medical benefit from doing it, so it may never be done.Incidentally, there seem to be a very few people whose cells seem to be a mixture of two different twins. Apparently, twin embryos can partly or fully merge into one embryo.[3] Such people are called chimeras or mosaics.Occasionally, there’s a pair of twins having different fathers, like these in the photo.[4]That can happen if the mother has sex with two different men while she is fertile. It’s called superfecundation.In theory, it’s entirely possible for those twins to merge and become a single person. Nobody like that has ever been detected but we can’t be sure it hasn’t happened.Finally, many women retain a few cells from children they have given birth to. If they had children from different men, they would have cells from those men.Footnotes[1] World's first baby born from new procedure using DNA of three people[2] Redirect Notice[3] Genetic Mosaics[4] Mom Discovers Her Twin Boys Have Different Dads — On The 'Maury' Show!