CAIE S1 2019 March — Question 1

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2019
SessionMarch
TopicConditional Probability
TypeBayes with complementary outcome

1 On each day that Tamar goes to work, he wears either a blue suit with probability 0.6 or a grey suit with probability 0.4 . If he wears a blue suit then the probability that he wears red socks is 0.2 . If he wears a grey suit then the probability that he wears red socks is 0.32 .
  1. Find the probability that Tamar wears red socks on any particular day that he is at work.
  2. Given that Tamar is not wearing red socks at work, find the probability that he is wearing a grey suit.