CAIE S1 2016 June — Question 3

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2016
SessionJune
TopicConditional Probability
TypeBayes with complementary outcome

3 The probability that the school bus is on time on any particular day is 0.6 . If the bus is on time the probability that Sam the driver gets a cup of coffee is 0.9 . If the bus is not on time the probability that Sam gets a cup of coffee is 0.3 .
  1. Find the probability that Sam gets a cup of coffee.
  2. Given that Sam does not get a cup of coffee, find the probability that the bus is not on time.