Question

A box contains four red marbles, six green marbles, and two blue marbles. What is the probability of pulling two green marbles followed by a blue marble if the marbles are pulled from the bag without replacement?

Answer 1

welcome to open study:)

Answer 2

What is the total marble count?

Answer 3

what do you think the answer is and is there any choices

Answer 4

i do not know. I thought it was 127/110

Answer 5

Yes, there are choices. I know the answer, but I do not know how to get it.

Answer 6

Actually that is the answer, i do not know how they got it

Answer 7

please put all the choices here and ill help you figure it out okay?

Answer 8

1/22
5/144
127/110
1/24

Answer 9

ill be right back okay then i will try to help unless @raffle_snaffle helps you

Answer 10

9/12 is not right at all

Answer 11

give me a sec I am thinking. I know how to solve it.

Answer 12

You sure those are your options?

Answer 13

yes

Answer 14

Okay I we need someone else here... @ganeshie8

Answer 15

Okay, I don't know if I'm doing this right, but tell me if it gets you the right answer e_o

Total marbles: 4 red + 6 green + 2 blue = 12 marbles
Ratio of green marbles to total marbles is 6:12, or 1:2.\[\text{green marble}\rightarrow\frac{green}{total}\rightarrow\frac{6}{12}=\frac{1}{2}\]This is for the FIRST green marble... now for the second
You now have one less green marble, so it's 5 green. Also, the total has gone down to 11. The ratio is now 5:11\[\text{SECOND green marble}\rightarrow\frac{green-1}{total}\rightarrow\frac{6-1}{11}=\frac{5}{11}\]

Answer 16

*sorry I made an error on the last equation\[\text{Second green marble}\rightarrow\frac{green-1}{total-1}\rightarrow\frac{6-1}{12-1}=\frac{5}{11}\]Now you're down two marbles from the total, so you have 10 marbles. The amount of blue marbles hasn't changed if you haven't picked out any, so the ratio is now 2:10\[\frac{blue}{total-2}\rightarrow\frac{2}{12-2}=\frac{2}{10}=\frac{1}{5}\]

I think you're supposed to do something with these ratios but I forgot e_o

Answer 17

The first problem in this link might help you http://www.varsitytutors.com/gre_math-help/how-to-find-the-probability-of-an-outcome

Answer 18

I'm aware of that, but I would rather the person come back to a solved problem than nothing. :)

Answer 19

Or, at least partially solved! ^_^

Answer 20

all good

Answer 21

have a good one