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mameadows
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what is the probability that your five number combination will be the winning combination in a lottery that involves the selection of random numbers from 1 through 20? the order of the five numbers is irrelevant.
 11 months ago
 11 months ago
mameadows Group Title
what is the probability that your five number combination will be the winning combination in a lottery that involves the selection of random numbers from 1 through 20? the order of the five numbers is irrelevant.
 11 months ago
 11 months ago

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wio Group TitleBest ResponseYou've already chosen the best response.1
When order matters, the total number of tickets (sample space) is \(20^5\) We can remove order by dividing out the number of permutations from the sample space. The \(5\) numbers can be permuted \(5!\) ways. Thus I ways say the probability is: \[ \frac {5!}{20^5} \]
 11 months ago

mameadows Group TitleBest ResponseYou've already chosen the best response.0
@wio can I leave my answer like that or do I have to actually multiply them out?
 11 months ago

wio Group TitleBest ResponseYou've already chosen the best response.1
You should multiply them out.
 11 months ago

wio Group TitleBest ResponseYou've already chosen the best response.1
\[ 5!=5\times4\times3\times2\times 1=20\times 3\times 2 \]
 11 months ago

wio Group TitleBest ResponseYou've already chosen the best response.1
\[ \frac{20\times 3\times 2}{ 20^5} = \frac{3\times 2}{20^4} = \frac{3}{10^4\times 2^3} \]At this point you may just want to use a calculator.
 11 months ago

mameadows Group TitleBest ResponseYou've already chosen the best response.0
this is what i thought it was: 20*19*18*17*16*15! / 15! * 5*4*3*2*1 = 1,860,480 / 120 = 15,504... you can only get one winning ticket so... 1 / 15,504 is that wrong?
 11 months ago

wio Group TitleBest ResponseYou've already chosen the best response.1
I don't understand the reasoning behind that so I can't tell you what is wrong with it.
 11 months ago

mameadows Group TitleBest ResponseYou've already chosen the best response.0
total no:(120)=29 use combination ,u have to select only 5 no's total no of ways=20 C 5 =20! / (15! * 5!) =20*19*18*17*16*15! / (15! * 5*4*3*2*1) =15,504 since only one will be correct out of these ways therefore answer is 1/15,504
 11 months ago

mameadows Group TitleBest ResponseYou've already chosen the best response.0
I meant to put (120)=20! at the top
 11 months ago

wio Group TitleBest ResponseYou've already chosen the best response.1
Well, the reason we use \(20^5\) instead of \(20!/15!\) is because it didn't say we can't have repeated numbers.
 11 months ago

wio Group TitleBest ResponseYou've already chosen the best response.1
It didn't say we can't chose something like 1 1 1 1 1
 11 months ago

mameadows Group TitleBest ResponseYou've already chosen the best response.0
got it... thx
 11 months ago
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