1 Andy ( \(A\) ), Beth ( \(B\) ), Chelsey ( \(C\) ), Dean ( \(D\) ) and Elly ( \(E\) ) have formed a quiz team. They have entered a quiz in which, as well as team questions, each of them must answer individual questions on a specialist topic. The specialist topics could be any of: food \(( F )\), geography \(( G )\), history \(( H )\), politics ( \(P\) ), science ( \(S\) ) and television ( \(T\) ). The team members do not know which five specialist topics will arise in the quiz.
Andy wants to answer questions on either food or television; Beth wants to answer questions on geography, history or science; Chelsey wants to answer questions on geography or television; Dean wants to answer questions on politics or television; and Elly wants to answer questions on history or television.
- Draw a bipartite graph to show the possible pairings between the team members and the specialist topics.
In the quiz, the first specialist topic is food, and Andy is chosen to answer the questions. The second specialist topic is geography, and Beth is chosen. The next specialist topic is history, and Elly is chosen. The fourth specialist topic is science. Beth has already answered questions so Dean offers to try this round. The final specialist topic is television, and Chelsey answers these questions.
- Draw a second bipartite graph to show these pairings, apart from Dean answering the science questions. Write down an alternating path starting from Dean to show that there would have been a better way to choose who answered the questions had the topics been known in advance. Write down which team member would have been chosen for each specialist topic in this case.
- In a practice, although the other team members were able to choose topics that they wanted, Beth had to answer the questions on television. Write down which topic each team member answered questions on, and which topic did not arise.