Hello!
The events considered in this problem are not independent. Therefore we have to use the formula of conditional probability:
`P(AB) = P(A)*P(B | A),`
where `A` and `B` are some events, `AB` is the event "`A` and `B`" and `B | A` is the event "`B` given event `A`".
We'll use this formula several times for all the seven elementary events, denote them `A_n.` The first event, `A_1,` is "the first card drawn is...
Hello!
The events considered in this problem are not independent. Therefore we have to use the formula of conditional probability:
`P(AB) = P(A)*P(B | A),`
where `A` and `B` are some events, `AB` is the event "`A` and `B`" and `B | A` is the event "`B` given event `A`".
We'll use this formula several times for all the seven elementary events, denote them `A_n.` The first event, `A_1,` is "the first card drawn is not a joker" (there are only 2 jokers, so to draw them on steps 6 and 7 all previous cards must not be a joker). Obviously `P(A_1)=52/54.`
Then we are interested in event `A_2,` "the second card is not a joker". The conditional probability `P(A_2 | A_1)` is also obvious: `54-1=53` cards remain and `52-1=51` are suitable, `P(A_2 | A_1)=51/53.`
Thus `P(A_1A_2)=52/54*51/53.`
The same way `P(A_1 A_2 A_3 A_4 A_5)=52/54*51/53*50/52*49/51*48/50.`
The events `A_6` and `A_7` are "the card drawn is a joker", and they give two more factors, `2/49` and `1/48.`
So the resulting probability is
`52/54*51/53*50/52*49/51*48/50*2/49*1/48.`
Some numbers are reduced and we obtain
`2/(54*53)=1/(27*53)=1/1431 approx 0.0007.` This is the answer.
Very awesome!!! When I seek for this I found this website at the top of all blogs in search engine. Pakarqq
ReplyDeleteVery useful post. This is my first time i visit here. I found so many interesting stuff in your blog especially its discussion. Really its great article. Keep it up. Pakarqq
it's really cool blog. Linking is very useful thing.you have really helped USA viisa Internetis
ReplyDelete