Answer:
a. 24
b. 12
Step-by-step explanation:
a. You can choose from 4 cities for the first performance, then from 3 cities, then from 2 cities, then the last city.
4 * 3 * 2 * 1 = 24
b. Think of the three performances in California as a unit. Within this unit, you can choose from 3 cities for the first one, then 2 cities for the second one, and finally 1 city for the last one.
3 * 2 * 1 = 6
Now you can have the 3 California performances first, followed by Denver, or Denver first followed by California.
6 * 2 = 12
