I forgot how to do that probability method that you would use in a question like you have a group of males and females in a line, and the females have to be separated by atleast one male. I can't remember distinctly, but it's like you would put the males down, and then use use combinations to determine where the females can sit. Thanks
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Can someone please teach me this probability method? (1 Viewer)
- Thread starter chriss95
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barbernator
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insertion method.
say the question was how many ways can we put 8 males and 5 females in a line, if no two females can be next to each other.
You place all the males in 8! ways. And then that leaves you with 9 spaces where the women can fit. So then you have 9P5 ways the women can be ordered in between the males.
hence the total ways of arranging is 8! x 9P5.
say the question was how many ways can we put 8 males and 5 females in a line, if no two females can be next to each other.
You place all the males in 8! ways. And then that leaves you with 9 spaces where the women can fit. So then you have 9P5 ways the women can be ordered in between the males.
hence the total ways of arranging is 8! x 9P5.
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RealiseNothing
what is that?It is Cowpea
Depends on whether or not what you are inserting is identical.
Capt Rifle
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So alternating, boy girl boy girl. Say there were 4 females, and 4 males. You need to arrange them in an alternate way so boy, girl, boy, girl. Now because you have four of each, it should look like this B G B G B G B G.
Do take note on how each girl has a boy next to her. Because there are four girl and four boys above we say 4! x 4! , because they can be rearranged. Also take note that B and G can switch positions so we multiply it again by 2!. Finally your answer should be 4! x 4! x 2!, which equals 1152.
Do take note on how each girl has a boy next to her. Because there are four girl and four boys above we say 4! x 4! , because they can be rearranged. Also take note that B and G can switch positions so we multiply it again by 2!. Finally your answer should be 4! x 4! x 2!, which equals 1152.