Question

An urn contains 9 red, 7 white, and 4 black balls. A ball is drawn at random. Find the probability that the ball is drawn is (i) red (ii) white (iii) red or white (iv) white or black (v) not white Select the correct answer from above options

Answer 1

Total number of Red balls = 9 Total number of white balls = 7 Total number of black balls = 4 Total number of balls = 9 + 7 + 4 = 20 We know, Probability of occurrence of an event = (Total number of favorable outcomes) / (Total number of outcomes) (i) P(getting a red ball) = 9/20 (ii) P(getting a white ball) = 7/20 (iii) P(getting a red or white) = (9 + 7)/20 = 16/20 = 4/5 (iv) P(getting a white or black) = (7 + 4)/20 = 11/20 (v) P(getting not white ball) = 1 – P(getting a white ball) = 1 – 7/20 = 13/20