A box of oranges is inspected by examining three randomly selected oranges drawn without replacement. If all the three oranges are good, the box is approved for sale, otherwise, it is rejected. Find the probability that a box containing 15 oranges out of which 12 are good and 3 are bad ones will be approved for sale.

Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the probability that both balls are red.

Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the probability that first ball is black and second is red. 

Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the probability that one of them is black and other is red. 

848.

An urn contains  4 red and 7 blue balls. Two balls are drawn at random with replacement. Find the probability of getting 2 red balls.

An urn contains  4 red and 7 blue balls. Two balls are drawn at random with replacement. Find the probability of getting 2 blue balls.

An urn contains  4 red and 7 blue balls. Two balls are drawn at random with replacement. Find the probability of getting one red and one blue ball.