Question

A bowl contains 8 blue marbles and 5 green marbles. Hannah randomly draws 4 marbles from the bowl. She does not replace the marbles after each draw. What is the probability that she draws 2 blue marbles and 2 green marbles?

Answer 1

a.28/429 b.5/429 c.4/13 d.56/143

Answer 2

well it looks like you are selecting

P(B, B, G, G) = 8/13 * 7/12 * 5/11 * 4/10

Answer 3

im sorry i dont understand what you mean :/

Answer 4

well there are 13 marbles 8 blue and 5 green

so if the 1st marble is selected is a blue, then P(B) = 8/13

since the marble isn't replaced there are now only 7 blue marbles and 12 in total... so selecting a 2nd blue marble is 7/12

so selecting a green next, there is 5 of them but only 11 left...

the 2nd green marble is 4 from 10

so multiply th probabilities to get

P(B, B, G, G) in that order

Answer 5

so nthe answer would be d.56/143

Answer 6

you need to consider other permutations also

Answer 7

A?

Answer 8

but that's on the assumption that of the 17160 possible you only want B, B, G, G

because if they way 2 blue and 2 green in any order...it changes...

and for the solution I posted you might like to multiply the probabilities again.

Answer 9

well A is my best guess for a very badly worded question.

Answer 10

guess we need to consider all the permutations
http://www.wolframalpha.com/input/?i=%284+choose+2%29*8%2F13+*+7%2F12+*+5%2F11+*+4%2F10

Answer 11

thank you very much

Answer 12

which one is correct ?

Answer 13

rational you were right :)

Answer 14

8c2*5c2/13c4=answer

Answer 15

280/715 further simplify it

Answer 16

56/143