AQA D2 2009 January — Question 4

Exam BoardAQA
ModuleD2 (Decision Mathematics 2)
Year2009
SessionJanuary
TopicDynamic Programming

4
  1. Two people, Raj and Cal, play a zero-sum game. The game is represented by the following pay-off matrix for Raj.
    Cal
    \cline { 2 - 5 }StrategyXYZ
    RajI- 78- 5
    \cline { 2 - 5 }II62- 1
    \cline { 2 - 5 }III- 24- 3
    \cline { 2 - 5 }
    \cline { 2 - 5 }
    Show that this game has a stable solution and state the play-safe strategy for each player.
  2. Ros and Carly play a different zero-sum game for which there is no stable solution. The game is represented by the following pay-off matrix for Ros, where \(x\) is a constant.
    Carly
    \cline { 2 - 4 }Strategy\(\mathbf { C } _ { \mathbf { 1 } }\)
    \cline { 2 - 4 }\cline { 2 - 3 } \(\operatorname { Ros }\)\(\mathbf { R } _ { \mathbf { 1 } }\)5\(\mathbf { C } _ { \mathbf { 2 } }\)
    \cline { 2 - 4 }\(\mathbf { R } _ { \mathbf { 2 } }\)- 2\(x\)
    \cline { 2 - 4 }4
    Ros chooses strategy \(\mathrm { R } _ { 1 }\) with probability \(p\).
    1. Find expressions for the expected gains for Ros when Carly chooses each of the strategies \(\mathrm { C } _ { 1 }\) and \(\mathrm { C } _ { 2 }\).
    2. Given that the value of the game is \(\frac { 8 } { 3 }\), find the value of \(p\) and the value of \(x\).