   1. Chapter 13 Class 12 Probability
2. Serial order wise
3. Ex 13.2

Transcript

Ex 13.2, 13 Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the Probability that (i) both balls are red. Two balls are drawn with replacement from a box Number of black balls in box = 10 Number of red balls in box = 8 Total number of balls in box = 10 + 8 = 18 P(both balls are red) = P(first ball is red) P(second ball is red given first is red ) = 8 18 8 18 = 4 9 4 9 = Ex 13.2, 13 Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the Probability that (ii) first ball is black and second is red. P(first ball is black & second is red) = P(first ball is black) P(second ball is red given first is black) = 10 18 8 18 = 5 9 4 9 = Ex 13.2, 13 Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the Probability that (iii) one of them is black and other is red. P(one ball is black & other is red) = P(first ball is black & second is red) + P(first ball is red & second is black) = 10 18 8 18 + 8 18 10 18 = 2 10 18 8 18 =

Ex 13.2 