An urn contains 6 red marbles and 9 white marbles. A marble is drawn and dropped back into urn. Then a second marble is drawn and dropped back into the urn. Both marbles were red. If another marble is drawn. What is the probability that it will be white?

Question

anonymous · Answer

"A marble is drawn and dropped back into urn. Then a second marble is drawn and dropped back into the urn." --- From the same urn isn't?

anonymous · Answer

The urn having "6 red marbles and 9 white marbles",

anonymous · Answer

Yes, and they are put back in, as soon as they have been drawn out.

anonymous · Answer

If it is the same urn then the answer is 3/5

anonymous · Answer

@FoolForMath , how?

anonymous · Answer

Because as it is the same urn, I don't think probability of drawing white in the first attempt is different from probability of drawing white in the second or third or ... unless of-course you are adding or removing marbles without replacement.

anonymous · Answer

thank you.

anonymous · Answer

Glad to help :)

anonymous · Answer

thanks FFM, i thought it's of different urn. .