[trikster]

I know this comes a little late for your interview, but this truly is a super easy question which everyone tried to make too complicate. I think you didn't really bother to read the question which was chances of taking both balls from the bag with ten red balls. This is obviously 1/4 or 25%. [img]/images/graemlins/grin.gif[/img]

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Hey - I have an interview tomorrow to which my possible employer told me there will be 'basic probability questions.' In surfing the web to prepare, I stumbled upon one that I am having trouble wrapping my mind around.

There are two bags of balls in front of you. You look inside and see that in 1 there are 10 red balls, and in one there are 5 red balls and 5 green balls. You close your eyes, and someone spins the bags around after closing them. You reach inside and select a red ball. You close your eyes again, he spins the bags, and you reach in and select another red ball. What are the chances that both balls you picked were from the bag with 10 red balls?


Seems like it should just be 10/15*9/14...but I am not sure. Sorry because I'm sure this is super basic.

James

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