In Piano Chords you saw that cases were required because you could use two, three, or four fingers. The number of combinations for each case was then added to determine the total number of combinations.
To see another example of solving combination problems by considering cases, read “Example 2” on page 532 of the textbook. As you read, pay special attention to what the phrase “at least” means when determining the number of combinations.
Complete “Your Turn” at the bottom of page 532 of the textbook. Answer
In Self-Check 4 you realized that when there are different scenarios, you have to add the combinations together to get the total number of combinations for all possible scenarios.
One of the most important pieces of identification you can have is your passport. Every country has different rules on how to obtain a passport. Consider the Australian Passport Offices’ “Documents that confirm your Australian citizenship and identity.” The document refers to lodgement. Lodgement refers to where you will be residing.
Assuming that you have each of the documents from categories A, B, and C and that you have two official documents that include your photograph, in how many ways can you supply the documentation required for combinations 1, 2, and 3?
Are there more combinations for lodgement in Australia or for lodgement overseas?
Why do you think the Australian Passport Office requires more documents from Category C than from Category A or Category B?
Save your responses in your course folder.