OCR MEI S1 2008 June — Question 4

Exam BoardOCR MEI
ModuleS1 (Statistics 1)
Year2008
SessionJune
TopicBinomial Distribution
TypeSingle batch expected count

4 A small business has 8 workers. On a given day, the probability that any particular worker is off sick is 0.05 , independently of the other workers.
  1. A day is selected at random. Find the probability that
    (A) no workers are off sick,
    (B) more than one worker is off sick.
  2. There are 250 working days in a year. Find the expected number of days in the year on which more than one worker is off sick.