CAIE S1 2016 November — Question 3

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2016
SessionNovember
TopicApproximating Binomial to Normal Distribution
TypeCombined binomial and normal events

3 On any day at noon, the probabilities that Kersley is asleep or studying are 0.2 and 0.6 respectively.
  1. Find the probability that, in any 7-day period, Kersley is either asleep or studying at noon on at least 6 days.
  2. Use an approximation to find the probability that, in any period of 100 days, Kersley is asleep at noon on at most 30 days.