Starter

1. Starter A café has recorded its customers’ preferences for tea and coffee, and whether or not they add sugar and milk to their drink. This table gives the results for customers who order a single drink. What is the probability that a customer selected at random has a cup of tea? 131/295 What is the probability that a customer adds both milk and sugar to their drink? 80/295 What is the probability that a customer has a drink with milk added? 185/295 What is the probability that a coffee drinker likes their coffee black with no sugar? 55/164

2. Note 5: Probabilities of Combinations of Events Events can be combined in various ways. The new corresponding outcomes need to be listed and then the probabilities can be calculated. Sometimes it is easier to draw up a table to display the new sample space.

3. Example: List all the possible differencesyou can roll with two normal dice in a table. 2 3 0 1 4 5 1 4 0 1 2 3 What is the probability of obtaining a: differenceof 2 a two and six on the dice a ‘two’ on the black die, and a ‘six’ on the white die. 3 2 1 0 1 2 3 1 2 2 0 1 =2/9 0 8/36 4 1 1 3 2 5 4 3 0 2 1 How many possible outcomes? = 1/18 2/36 36 1/36

4. Page 281 Exercise M