A bag contains 12 pairs of socks. Four socks are picked up at random. Find the probability that there is at least one pair.

In a two children family, find the probability that there is at least one girl in a family.

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 bag contains 5 white and 7 black balls,3 balls are drawn at random.Find the probability that (i)all are white,(ii)one white and two black.

A bag contains 7 red and 4 black balls, 3 balls drawn at random. Find the probability that (i) all are red (ii) one red and 2 black.

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

A bag contains 12 blue balls and x red balls. If one ball is drawn at random (i) what is the probaility that it will be a red ball ? (ii) If 8 more red balls are put in the bag, and if the probability of drawing a red ball will be twice that of the probaility in (i), then find x.