An urn contains five golden balls and fifteen black balls Yo

An urn contains five golden balls and fifteen black balls. You will randomly draw four balls from the urn: if there is at least three golden balls among the balls you drew, you will score one point (zero otherwise). Then, the balls are placed back into the urn and the process is repeated four more times.

– What is the expected number of drawn golden balls per trial?

– In any given trial, what is the probability that you score one point?

– Assume that if you are able to score three or more points at the end of five trials, you will win ten thousand dollars. what is the probability that you win?

Solution