CAIE S2 2011 November — Question 7

Exam BoardCAIE
ModuleS2 (Statistics 2)
Year2011
SessionNovember
TopicPoisson Distribution
TypeJoint probability of separate processes

7 The numbers of men and women who visit a clinic each hour are independent Poisson variables with means 2.4 and 2.8 respectively.
  1. Find the probability that, in a half-hour period,
    (a) 2 or more men and 1 or more women will visit the clinic,
    (b) a total of 3 or more people will visit the clinic.
  2. Find the probability that, in a 10 -hour period, a total of more than 60 people will visit the clinic.