CAIE S1 2020 June — Question 1

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2020
SessionJune
TopicConditional Probability
TypeTree diagram with two-stage events

1 Juan goes to college each day by any one of car or bus or walking. The probability that he goes by car is 0.2 , the probability that he goes by bus is 0.45 and the probability that he walks is 0.35 . When Juan goes by car, the probability that he arrives early is 0.6 . When he goes by bus, the probability that he arrives early is 0.1 . When he walks he always arrives early.
  1. Draw a fully labelled tree diagram to represent this information.
  2. Find the probability that Juan goes to college by car given that he arrives early.