Ex 15.1, 8

Transcript

Ex15.1, 8 A bag contains 3 red balls and 5 black balls. A ball is drawn at random from the bag. What is the probability that the ball drawn is (i) red? Total number of balls in the bag = 5 + 3 = 8 Number of red balls = 3 Probability of getting a red ball = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑟𝑒𝑑 𝑏𝑎𝑙𝑙𝑠)/(𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑏𝑎𝑙𝑙𝑠) = 3/8 Ex15.1, 8 A bag contains 3 red balls and 5 black balls. A ball is drawn at random from the bag. What is the probability that the ball drawn is (ii) not red? Total number of balls in the bag = 8 Probability of not getting a red ball = Probability of getting blackballs = (𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓𝑏𝑙𝑎𝑐𝑘 𝑏𝑎𝑙𝑙𝑠)/(𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑏𝑎𝑙𝑙𝑠) = 5/8 Method 2 Probability of not getting red ball = 1 − Probability of getting a red ball = 1 – 3/8 = 5/8