Counting rules

Question

a tourist in France wants to visit 12 different cities.if the route is randomly selected, what is the probability that she will visit the cities in alphabetical order?

Answer 1

There's only one way to arrange the names of the12 cities in alphabetical order, but there are 12! ways to arrange those city names w/o regard to alphabetical order.

 

12! = 479001600 so P(alphabetical order = 2.087676 •10^-9, i.e. 1/that 12!