A box contains 20 red and 15 black balls. Two balls are drawn from the box one after the other without replacement. What is the probability that both drawn balls are red ?

An urn contains 8 white and 4 red balls. Two balls are drawn from the urn one after the other without replacement. What is the probability that both drawn balls are white ?

An urn contains 10 black and 5 white balls. Two balls are drawn from the urn one after the other without replacement. What is the probability that both drawn balls are black?

An urn contains 10 black and 5 white balls. Two balls are drawn from the urn one after the other without replacement. What is the probability that both drawn balls are black?

An urn contains 10 black and 5 white balls. Two balls are drawn from the nm one after the other without replacement. What is the probability that both drawn balls are black?

(i) An urn contains 7 red and 3 black balls. Two balls are drawn one after another without replacement. What is the probability that the second ball is red if it is know that the first ball drawn is red. (ii) A box contains 8 red and 10 green balls. Two balls are drawn one after another without replacement. What is the probability that the second ball is green if it is know that the first ball drawn is red.

A box contains 3 white and 2 black balls. Two balls are drawn at random one after the other. If the balls are not replaced. what is the probability that both the balls are black ?