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#1
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HELP!!
Im not good with math, can someone explain to me how u get this answerignore the dots on left, only way i could get it to indent
. 2 C =1081 . 47 |
#2
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Re: HELP!!
[ QUOTE ]
Im not good with math, can someone explain to me how u get this answerignore the dots on left, only way i could get it to indent . 2 C =1081 . 47 [/ QUOTE ] C(47,2) or 47c2 = 47*46/(2*1) = 1081. See more details here. Note that you use Google to evaluate this by typing in 47 choose 2. |
#3
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Re: HELP!!
where did u get the 46 from?
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#4
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Re: HELP!!
[ QUOTE ]
where did u get the 46 from? [/ QUOTE ] Since we are choosing 2, the numerator has 2 terms counting backwards from 47, so it is 47*46. This comes from the fact that C(47,2) = 47!/(47-2)!/2! = 47!/45!/2!, and since 47! = 47*46*45!, the 45! cancels out to give 47*46/2!. Here are a couple more examples: C(47,3) = 47*46*45/(3*2*1) C(52,5) = 52*51*50*49*48/(5*4*3*2*1) |
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