Question

A bag contains 5 chocolate, 3 peanut butter, 4 oatmeal and 4 sugar cookies.

If 2 cookies are selected randomly, what is the probability that they will be the same kind?

Answer 1

RESPOND QUICK

Answer 2

16 cookies
lets do chocolate first
\[\frac{ 5 }{ 16 }\] that first one will be chocolate \[\frac{ 4 }{ 16 }\] that the next one will be chocolate or \[\frac{ 1 }{ 4 }\]

Answer 3

oops did that wrong

Answer 4

\[\frac{ 4 }{ 15 }\] i meant

Answer 5

\[\frac{ 3 }{ 16 }\] is the first one will be peanut butter \[\frac{ 2 }{ 15 }\] that the second one will be the same

Answer 6

\[\frac{ 4 }{ 16 }\] that the first one is oatmeal/sugar \[\frac{ 1 }{ 4 }\] when simplified \[\frac{ 3 }{ 15 } or \frac{ 1 }{ 5 }\] that the second one will be as well

Answer 7

I still dont get what your doing

Answer 8

WHATS the answer I need this urgently

Answer 9

well whats your options

Answer 10

You can get 2 chocolate, or 2 peanut butter, or 2 oatmeal, or 2 sugar
\[\Large \frac{{5\choose 2}}{{16\choose 2}}+\frac{{3\choose 2}}{{16\choose 2}}+\frac{{4\choose 2}}{{16\choose 2}}+\frac{{4\choose 2}}{{16\choose 2}}\]

Answer 11

a. 6.7%
b. 30%
c.9%
d. 93.3%

Answer 12

This doesn't give me any of these answers. I get 25/120=5/24=20.8% Even if I try it using @KlOwNlOvE 's method which gives me the same result, it's still 5/24

Answer 13

I got the answer choices off my test so I think there's a problem

Answer 14

(No wonder I couldn't find the answers...)

Answer 15

hmm.. weird.

Answer 16

I know right

Answer 17

Hopefully the answer choices are wrong o.o or maybe they incorrectly worded the question, or made a typo (maybe they mean 6 instead of 5 chocolate or smtg? :S)

Answer 18

about the test I got a 90% because I missed this question 9/10

Answer 19

=( can you check it with your teacher?

Answer 20

No Im kinda bummed right now cause I cant retake it but at least its better than a 80%

Answer 21

Well I mean like can you ask the teacher what the answer is, and how they get to it? Because there is most likely a typo in this.

Answer 22

But I cant cause I'm taking an online course my parents signed me up for with NO TEACHER SUPPRORT

Answer 23

Thats why im asking people on open study to help

Answer 24

ohh i see :s

Answer 25

Maybe were wrong on the question and its not a typo

Answer 26

I haven't got a typo in this whole course so its rare we dint get the answer

Answer 27

I've done quite a few of these kinds of problems recently, so it feels very fresh in my head so I'm not sure what I could have done wrong. Furthermore, this type of problem here http://math.stackexchange.com/questions/294850/3-balls-drawn-from-1-urn-probability-all-same-color-with-without-replacement is very similar to what you are asked, except replace cookies for balls, and they are interested in 3 identical balls, but you it's 2 identical cookies

Answer 28

Although I did assume without replacement.. maybe the question wants it with replacement? :S

Answer 29

I guess so
Say.. We were chatting for a long time almost an hour

Answer 30

I gave you a medal and I fanned you

Answer 31

lol I didn't realize how long. I have been going throgh other questions and other windows too lol, multitasking. I just don't like leaving the person who asked the question without a full clear solution :S

Answer 32

Thanks for spending your time and commitment

Answer 33

your welcome :). Good luck with the rest of your course !

Answer 34

Thank you! By the way right now I'm studying Odds in Favor and Odds Against and its pretty hard

Answer 35

ahh . Well if you have more questions, I should be able to help :) I like probability questions hehe

Answer 36

Say.. Its 7:32 right now so its time for my dinner so I have to say goodbye. Maybe we will chat again someday but my course end tomorrow so I wont be in open study that often

Answer 37

Bye Bye

Answer 38

ok, bye!