Answer to Question #106586 in Statistics and Probability for Junaid

Question

An overnight express company must include two cities on its route. How many different routes are possible, assuming that in which order the cities are included in the routing is important?

Number of different routes?

Answer 1

Let n be the total number of cities. The total number of routes consisting of two routes is given by

$Routes=\frac{n!}{(n-2)!}$

For instance if there are 2 cities, the number of routes is $\frac{2!}{0!}=2$