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Suppose: 55% of adults like coffee. 25% of adults like tea. 45% of adults like cola.
and 15% drink both coffee and tea 5% drink all beverages 25% drink both coffee and cola 5% drink only tea
a) What percent of adults drink only cola?
b) What percent drink none of these beverages?
Note: This is a high school problem; question may be easily solved. Don't blame me for my ineptitude!
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I remember doing these problems in my pre-calc class. Forgot now.
edit: use a tree diagram
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Did you try making a Venn Diagram?
Have each region represent a specific variable, and there are 7 regions non-overlapping regions, coffee, tea, cola, coffe/cola, coffe/tea, cola/tea, and coffe/cola/tea. rewrite the information given and you have a system of 7 varialbes and equations and you can just solve from there.
Also, this isn't a probability problem.
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45 cola - 25 coffeecola - 5 all - (25tea - 15coffeetea - 5all - 5onlytea)teacola = 15 onlycola?
100 - (15coffeetea + 5all + 25coffeecola + 5onlytea + 0teacola + 15onlycola + (55coffee - 15coffeetea - 5all - 25coffeecola)onlycoffee = 25none?
i always sucked at probability/statistics/w/e so yeah iuno mang
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^^Avidkeystamper has a clever solution, I've actually never seen this type of problem in my life despite having just taken multivariable calc(lol...). I really wouldn't know how to do it without thinking a lot.
On January 08 2009 14:06 YianKutKu wrote: I remember doing these problems in my pre-calc class. Forgot now.
edit: use a tree diagram You are a hunters player, yes? I think I've seen you around bnet.
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More effort for homework threads please. All you did was post the problem, what do you know about the problem thus far if anything?
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Make a Venn Diagram of all three. First one is pretty simple once you get it going but the second one tricked me, though I think I got it right (I took math 12 last year, and I'm in arts now so I'm not really that fresh @ this stuff), however:
Answers should be: a)15% b)20%
Btw you should say that 55% of adults drink coffee/tea/cola, because liking and drinking can be two different things (hope that didn't change the answer).
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Do you have the answer key? can you tell us the answers? im curious now.
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Well I tried the venn diagram with 3 overlaps and each section labeled a different drink. But I got confused in the process of trying to find the answer for each question. I know about the addition rules for disjoint events like P(A) + P(B)=P(A or B).
This problem has the overlap and I honestly don't have any idea what to do. I think it has something to do with P(A or B)=P(A) + P(B) - P(A and B) but there's three variables so that got me pretty confused.
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On January 08 2009 14:17 Resonance wrote: Make a Venn Diagram of all three. First one is pretty simple once you get it going but the second one tricked me, though I think I got it right (I took math 12 last year, and I'm in arts now so I'm not really that fresh @ this stuff), however:
Answers should be: a)15% b)15%
Btw you should say that 55% of adults drink coffee/tea/cola, because liking and drinking can be two different things (hope that didn't change the answer). Oh I just copied the problem from the book. I don't have an answer key though =[
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a) 15% b) 20%
do these add up
I have alot of pracitce with these and this was a rather easy one as long as i know how to add
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I had the exact same question, ah I forgot though! Solve for coffee and tea and then the remainder should be coke.
A= Coffee B= Tea
P(55)+ P(25)-P(15)= 55
So the remaining should be 45% who like coke
Actually I'm not sure if that's right but I think .45 is one of the answers
Edit: NVM, look at the diagram above ^^^^^^
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That sucks no answers how are you supposed to know your doing a question right.
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yeah they do divinek, i just realized the mistake in mine was that i assumed the phrase "coffee and tea" meant "coffee, tea, but not cola" and etc etc etc so it led to me calculating that tea+cola and not coffee was 0
i dunno man honestly it could go both ways
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Fucking hell everybody has different answers, I am going to do this again.
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Ah I get the first, still wondering what I subtract to get the second.
Yeah my teacher gave me an even problem; I don't know why. The second answer seems right. Thanks. I never liked venn diagrams =/
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yeah I made another mistake Divinek has it right.
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On January 08 2009 14:27 Resonance wrote: No answer? Man that's a bad teaching method how are you supposed to know if what you are doing is right?
Anyway here is my logic for both of your questions:
For the first one it's pretty simple, just find the only Cola drinkers %.
For the second, what I did was get all the percentages (after broken down, 15+25+5+15+5+10+0=75)
Then just go 100% - 75 = 25...rofl yeah ok so I made that mistake there I'm really fucking tired haha
So answers are 15% and 25%
When you get to 3rd/4th year math courses atleast none of the books have answers, at all.
It's suprising how many people got this wrong. Pictures really do help, always, always, always.
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On January 08 2009 14:30 Divinek wrote:Show nested quote +On January 08 2009 14:27 Resonance wrote: No answer? Man that's a bad teaching method how are you supposed to know if what you are doing is right?
Anyway here is my logic for both of your questions:
For the first one it's pretty simple, just find the only Cola drinkers %.
For the second, what I did was get all the percentages (after broken down, 15+25+5+15+5+10+0=75)
Then just go 100% - 75 = 25...rofl yeah ok so I made that mistake there I'm really fucking tired haha
So answers are 15% and 25% When you get to 3rd/4th year math courses atleast none of the books have answers, at all. It's suprising how many people got this wrong. Pictures really do help, always, always, always. it was a semantics issue, my method was perfectly fine if in the OP the phrases like "cola and coffee" meant exclusive of tea
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On January 08 2009 14:30 Peter[Deuce] wrote: Ah I get the first, still wondering what I subtract to get the second.
Suppose: 55% of adults like coffee. 25% of adults like tea. 45% of adults like cola.
and 15% drink both coffee and tea 5% drink all beverages 25% drink both coffee and cola 5% drink only tea
ok so you have that right
First thing I like to do is put the a+b+c one in, the five percent, then you can throw in the coffee and tea's 10 percent to get 15, and then the coffee and cola's 20 to get 25. then you put 5% in tea, which you dont even need to be supplied with, and fill in the rest based on the 'suppose' just by subtracting what you have from what you need. and then subtract everything in there from 100 to get the 20.
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Divinek's has P(Coffee and cola)=20% when it's 25%
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On January 08 2009 14:30 Divinek wrote:Show nested quote +On January 08 2009 14:27 Resonance wrote: No answer? Man that's a bad teaching method how are you supposed to know if what you are doing is right?
Anyway here is my logic for both of your questions:
For the first one it's pretty simple, just find the only Cola drinkers %.
For the second, what I did was get all the percentages (after broken down, 15+25+5+15+5+10+0=75)
Then just go 100% - 75 = 25...rofl yeah ok so I made that mistake there I'm really fucking tired haha
So answers are 15% and 25% When you get to 3rd/4th year math courses atleast none of the books have answers, at all. It's suprising how many people got this wrong. Pictures really do help, always, always, always.
Lol I'm suprised it wrong too, I did this stuff last year and I remember it was so easy, but I have forgotten so much.
Ah well I'm not in math right now so I guess I have an excuse.
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On January 08 2009 14:33 Peter[Deuce] wrote: Divinek's has P(Coffee and cola)=20% when it's 25% no see his P(coffee and cola) is split among the 5 all3 + the 20 coffee/cola/NOTtea which checks out
P(coffee, cola, not tea) != P (coffee, cola)
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I don't know. I figured that P(Cola and Tea)=0% because 5%(tea only)+15%(Coffee and tea)+5%(All)=25% already.
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On January 08 2009 14:34 SpiritoftheTunA wrote:Show nested quote +On January 08 2009 14:33 Peter[Deuce] wrote: Divinek's has P(Coffee and cola)=20% when it's 25% no see his P(coffee and cola) is split among the 5 all3 + the 20 coffee/cola/NOTtea which checks out P(coffee, cola, not tea) != P (coffee, cola) Ah!
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On January 08 2009 14:35 Peter[Deuce] wrote: I don't know. I figured that P(Cola and Tea)=0% because 5%(tea only)+15%(Coffee and tea)+5%(All)=25% already. yeah i did something similar the first time, not realizing the mistake in thinking i just pointed out
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Thanks guys. First time in statistics where I was confused =O
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a) 15 b) 20
2nd year math major approved
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On January 08 2009 14:40 zeks wrote:a) 15 b) 20 2nd year math major approved
but did you like my drawing
And no worries for the help, if you need anymore in the future feel free to pm me if you like.
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On January 08 2009 14:13 Fontong wrote:^^Avidkeystamper has a clever solution, I've actually never seen this type of problem in my life despite having just taken multivariable calc(lol...). I really wouldn't know how to do it without thinking a lot. Show nested quote +On January 08 2009 14:06 YianKutKu wrote: I remember doing these problems in my pre-calc class. Forgot now.
edit: use a tree diagram You are a hunters player, yes? I think I've seen you around bnet.
Yup. Haven't been playing a lot of 3v3's though lately.
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