CAIE S1 2018 June — Question 3

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2018
SessionJune
TopicHypergeometric Distribution
TypeCalculate expectation and variance

3 Andy has 4 red socks and 8 black socks in his drawer. He takes 2 socks at random from his drawer.
  1. Find the probability that the socks taken are of different colours.
    The random variable \(X\) is the number of red socks taken.
  2. Draw up the probability distribution table for \(X\).
  3. Find \(\mathrm { E } ( X )\).