Vinu P.

asked • 08/20/20

Data Management Probability Questions

1. The following letters are rearranged BROWN. What is the probability that the BRO are together and in this order


2.Aliens landed on Costco to buy some groceries and donate blood. The American president is sending an 8-member committee team of scientists to investigate this. His choices include 7 Biologists, 10 Chemists, 3 Physicists, and 4 Linguists. What is the probability that the team he selects consist:

a) All Biologists?

b) At least 2 Linguists?

c) Three times as many Chemists as there are Biologists?

*For a what I was thinking, since there are only 7 biologists, would that mean the 7 biologists are chosen and 1 other person is chosen from the rest or it is not possible because it is only possible for 7 biologists not 8


3.The first four games of a World Series are played between the Blue Jays and the Phillies who are evenly matched. Using a tree diagram, find the probability that

a)The Phillies win the series four straight

b)The Blue Jays win three of the first four games

c)The Blue Jays win the opener (first-game) of the series.

*For c, is it if Blue Jays win only the first game or they win the other games including the first one?

1 Expert Answer

By:

Keith S.

tutor
I don't think it will let me post a second video. In that case, Probability=#EventYou'reAskedAbout/#TotalWays a) 7C7*(24-7)C1 = 7*17, all divided by 24C8 =====.0001618 b) P(>2 Linguists) = 1 - P(0 Linguists) - P(1 Linguist) = = 1 - (20C8 - 4C1*20C7)/24C8 ====== .4071 c) There are two options in this scenario: P(3 Chems, 1 Bio, 4 Else) = (10C3*7C1*7C4) / 24C8 + P(6 Chems, 2 Bio, 0 Else) = (10C6*7C2*7C0) / 24C8 = 33810 / 735471 == .04597
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08/20/20

Keith S.

tutor
Oh wow that did not format well. Let me know if any of that needs reclarification
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08/20/20

Aisha H.

is it possible to format it better
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08/20/20

Keith S.

tutor
I can't really know how the formatting will end up from my end. Just look for the "a)', "b)", and "c)" sections, and write those sections down in a less chaotic way, then see if that helps to make sense of them
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08/20/20

Elaine C.

I got around 1.25 for b) is there any way to explain it?
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08/20/20

Keith S.

tutor
Right. So first off, your answer will have to be between 0 and 1. Now, for part B, you need to know the probability of at least 2 Linguits, but that's just the opposite of at most 1 linguist (which makes the answer just 1 minus the probability of at most 1 linguist). That is 2 cases: 0 or 1 linguists. If there are 0 linguists, then the 8 spots can be filled by any of the 20 remaining people. That's 20C8. For the 1 case, there are 4C1 ways to choose 1 linguist, times 20C7 for the 7 remaining spots out of 20 people. Thats 20C8 + 4*20C7. Now divide that sum by 24C8, since that's how many total ways to make this 8-person group out of all of the 24 people. Thus, the full answer is 1- (20C8 +4*20C7)/(24C8) which is .4071.
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08/20/20

Elaine C.

Thank you for the explanation, I caught the mistake I made and got the final answer .4071
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08/20/20

Vinu P.

thank you for your help, i understand it much better now!
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08/20/20

Vinu P.

for the first question can it be arranged in 6 ways cause you can do N,BRO,W or BRO,N,W or N,W,BRO so instead the probability would be 3!/5!?
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08/20/20

Sehun O.

yea @ vinu you are correct. Idk what keith is on but he is def wrong about question 1 being 1/40. the answer is 1/20, or 5%.
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08/20/20

Vinu P.

ok tyy i was honestly thinking that i was wrong lol
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08/20/20

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