CAIE S1 2018 June — Question 5

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2018
SessionJune
TopicDiscrete Probability Distributions
TypeConstruct probability distribution from scenario

5 A game is played with 3 coins, \(A , B\) and \(C\). Coins \(A\) and \(B\) are biased so that the probability of obtaining a head is 0.4 for coin \(A\) and 0.75 for coin \(B\). Coin \(C\) is not biased. The 3 coins are thrown once.
  1. Draw up the probability distribution table for the number of heads obtained.
  2. Hence calculate the mean and variance of the number of heads obtained.