A box contains 7 white and 5 black balls two are drawn at random find the probability that they are not of the same colour when
the balls are drawn at a time

A box contains 7 white and 5 black balls three are drawn at random find the probability that they are not of the same colour when one by one without replacement.

A bag contains 5 white and 4 black balls.If 3 balls are drawn at random,find the probability that at least two of them are white.

A bag contains 5 white and 4 black balls. If 3 balls are drawn at random, find the probability that at least two of them are white.

An urn contains 9 red, 7 white, and 4 black balls if two balls are drawn at random the probability that both the balls are red is

A box contains 6 white balls and 4 black balls, A ball is drawn at random from the box. What is the probability that the ball is white.

A bag contain n white and n black balls, all of equal size. Balls are drawn at random. Find the probability that there are both white and black balls in the draw and that the number of white balls is greater than that of black balls by 1.

A box contains 4 white and 6 red balls if 2 balls are drawn at random find the expectation of the number of red balls

A bag contains 3 red, 7 white, and 4 black balls. If three balls are drawn from the bag, then find the probability that all of them are of the same color.

An urn contains 10 red and 8 white balls. One ball is drawn at random. Find the probability that the ball drawn is white.

An urn contains m white and n black balls. A ball is drawn at random and is put back into the urn along with k balls of the same colour as that of the ball drawn. a ball is again drawn at random. Show that the probability of drawing a white ball now does not depend on k.