CAIE S1 2021 November — Question 3

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2021
SessionNovember
TopicDiscrete Probability Distributions
TypeSampling without replacement

3 A bag contains 5 yellow and 4 green marbles. Three marbles are selected at random from the bag, without replacement.
  1. Show that the probability that exactly one of the marbles is yellow is \(\frac { 5 } { 14 }\).
    The random variable \(X\) is the number of yellow marbles selected.
  2. Draw up the probability distribution table for \(X\).
  3. Find \(\mathrm { E } ( X )\).