CAIE S1 2016 November — Question 3

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2016
SessionNovember
TopicBinomial Distribution
TypeMultiple independent binomial calculations

3 Visitors to a Wildlife Park in Africa have independent probabilities of 0.9 of seeing giraffes, 0.95 of seeing elephants, 0.85 of seeing zebras and 0.1 of seeing lions.
  1. Find the probability that a visitor to the Wildlife Park sees all these animals.
  2. Find the probability that, out of 12 randomly chosen visitors, fewer than 3 see lions.
  3. 50 people independently visit the Wildlife Park. Find the mean and variance of the number of these people who see zebras.