A Bag contains 6 red Marbles, 9 blue marbles and 5 green marble. you withdraw one marble, replace it, and then withdraw another marble. what is the probability that you do not pick two green marbles?
2006-07-29 10:03:15 · 7 answers · asked by schoolboi_000 1 in Science & Mathematics ➔ Mathematics
(15/20)^2 = (3/4)^2 = 9/16 = 56.25%
2006-07-29 10:11:44 · answer #1 · answered by bogusman82 5 · 0⤊ 0⤋
Well it's not 15/16 or 1/4.
The probability of not getting green is 15/20 or 3/4.
The probabilty of not getting green the second time is still 3/4 because you replaced the first marble. Multiplying 3/4 * 3/4, the answer is 9/16.
2006-07-29 10:20:36 · answer #2 · answered by MollyMAM 6 · 0⤊ 0⤋
15 in 16 and 1 in 4, not much of a variation among answers, huh kid? Guessing would do you better than askign out here.
How about if you reason it out, right or wrong at least it is your work.
What is the probability of picking the green marble? Five in 20 (1 in 4), right?
If you replace it, then then the second selection does not depend on the first, independent events. Then the chance of picking a green the second time is the same, 1 in 4.
So the chances of both is 1 in 16. This was selecting the green, so not selecting a green is 1 - the prior probability.
Who was right? Remember who showed you who was right.
2006-07-29 10:15:43 · answer #3 · answered by Anonymous · 0⤊ 0⤋
for first time you have 9+5+6 marbles to withdraw so you have 5/20(1/4) probability
and like this for second time so all of probability
is 1/4 * 1/4=1/8
2006-07-29 10:12:59 · answer #4 · answered by Anonymous · 0⤊ 0⤋
The probability that you pick a green marble on any given trial is 5/20 = 0.25. Each pick is an independent event and thus the probability for each pick is 0.25. In order to meet the criteria given in the question there must be two consecutive successful draws. To find the probability, multiply:
0.25*0.25 = 0.0625 = 6.25%
There is only a 6.25% chance that you will pick two green marbles. Therefore, there is a 93.75% chance that you will NOT pick two green marbles.
2006-07-29 11:24:25 · answer #5 · answered by jimbob 6 · 0⤊ 0⤋
Since there are 20 marbles total, and five of them are green, there is a one-in-four chance you'll pick a green marble when you withdraw the first one. After that it gets confuddled. But the answer to the question is 1-in4 chance.
2006-07-29 10:09:41 · answer #6 · answered by nitr0bike 4 · 0⤊ 0⤋
15 in 16
2006-07-29 10:06:26 · answer #7 · answered by tomgreenfanus 3 · 0⤊ 0⤋