CAIE S1 2012 November — Question 5

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2012
SessionNovember
TopicBinomial Distribution
TypeCombined probability with other distributions

5 A company set up a display consisting of 20 fireworks. For each firework, the probability that it fails to work is 0.05 , independently of other fireworks.
  1. Find the probability that more than 1 firework fails to work. The 20 fireworks cost the company \(
    ) 24\( each. 450 people pay the company \)\\( 10\) each to watch the display. If more than 1 firework fails to work they get their money back.
  2. Calculate the expected profit for the company.