Question

Sixth Grade Probability (Independent and Dependent Events) Help?? Medal+Fan!

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

You already know there are 16 cookies, now you have to set up the problem and solve it

Answer 2

P(both chosen are peanut butter cookies), Now with that provided you should be able to write out the probability for two of the same cookies being picked, tell me if you need help

Answer 3

I don't get it, because wouldn't the probability change between the numbers of the cookies? Like, there's 5 chocolate but only 3 peanut butter, etc... or I guess not because it's two for everything? But I still don't get how to get the probability @Night-Watcher

Answer 4

3/16 * 2/15 Multiply them two, then simplify the answer.

Answer 5

1/40 @Night-Watcher

Answer 6

Ok...but that doesn't answer what the probability is? 1/40 is none of my choices.

Answer 7

My choices are:
a. 5/24
b. 5/7
c. 5/12

Answer 8

Someone heeeeelp :(

Answer 9

u should use ppermutations and combinations
example: selecting 2 from peanut is 3C2/16C2
Similarly 2 of any kind is
3C2+5C2+4C2+4C2.it should be divided by 16C2

Answer 10

What do I have to do then? Divide all of those?

Answer 11

nCr=n!/(r!*(n-r)I
so 3C2=3
5C2=20
4C2=6
add above and divide it by 16C2 which is 120

Answer 12

sorry 5C2=10

Answer 13

are u able to understand???

Answer 14

(3+10+6+6)/120

Answer 15

(15)/120?

Answer 16

8.

Answer 17

25/120

Answer 18

thats what i meant oops

Answer 19

4 with 8 remaining

Answer 20

25/120=5/24

Answer 21

agh sorry
i keep typing in wrong number on my calculator

Answer 22

Ok 5/24 is the answer? Thanks! Can you explain to me what all that C stuff was all about so I leave with something because I didn't really get what you did

Answer 23

actually, nCr is selecting r objects in total of "n".
SO if u want to select 2 obj out of 10 then it is 10C2.
nCr formula=n!/(r!*(n-r)!)
so 10C2=10!/(2!*8!)
where 10!=10*9*8*....2*1
Here in this sum u have to select 2 of same kind which can be either peanut,chocolate,cookies or oatmeal.
hence it is 5C2+3C2+4C2+4C2.
total bag have 16 cookies.SO selecting any two is 16C2
Answer is( 5C2+3C2+4C2+4C2)/16C2

Answer 24

if u still did not understand ask me
i wil help u