CAIE S2 2011 June — Question 1

Exam BoardCAIE
ModuleS2 (Statistics 2)
Year2011
SessionJune
TopicPoisson Distribution
TypeScaled time period sums

1 A hotel kitchen has two dish-washing machines. The numbers of breakdowns per year by the two machines have independent Poisson distributions with means 0.7 and 1.0 . Find the probability that the total number of breakdowns by the two machines during the next two years will be less than 3 .