Chapter 15, Problem 1RE

Explanation of Solution

List:

A list is considered as the collection that will retain the order of the elements.

Set:

A set is considered as unordered collection of unique elements.

Choice:

The better choice for the invoice that contains a collection of the items purchased would be list.

Reason:

Maintaining the order is considered to be important in the invoice and also a list allows the duplicate items to be listed which could be an expected possibility on an invoice.