OCR MEI AS Paper 2 2019 June — Question 5

Exam BoardOCR MEI
ModuleAS Paper 2 (AS Paper 2)
Year2019
SessionJune
TopicTree Diagrams
TypePopulation partition tree diagram

5 Each day John either cycles to work or goes on the bus.
  • If it is raining when John is ready to set off for work, the probability that he cycles to work is 0.4.
  • If it is not raining when John is ready to set off for work, the probability that he cycles to work is 0.9 .
  • The probability that it is raining when he is ready to set off for work is 0.2 .
You should assume that days on which it rains occur randomly and independently.
  1. Draw a tree diagram to show the possible outcomes and their associated probabilities.
  2. Calculate the probability that, on a randomly chosen day, John cycles to work. John works 5 days each week.
  3. Calculate the probability that he cycles to work every day in a randomly chosen working week.