CAIE S1 2018 November — Question 3

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2018
SessionNovember
TopicBinomial Distribution
TypeCombined probability with other distributions

3 Jake attempts the crossword puzzle in his daily newspaper every day. The probability that he will complete the puzzle on any given day is 0.75 , independently of all other days.
  1. Find the probability that he will complete the puzzle at least three times over a period of five days.
    Kenny also attempts the puzzle every day. The probability that he will complete the puzzle on a Monday is 0.8 . The probability that he will complete it on a Tuesday is 0.9 if he completed it on the previous day and 0.6 if he did not complete it on the previous day.
  2. Find the probability that Kenny will complete the puzzle on at least one of the two days Monday and Tuesday in a randomly chosen week.