There are n cities. What is the number of airlines that connected 3 different cities (airline from city A to city B is different with airline from city B to city A)?
Choose the correct choice from the following:
A) n(n-1) B) n(n+1) C) n(n-1)/2 D) n(n+1)/2 E) n(n-2)
First of all, the possible number of airlines is n. Then, the possible number of airlines departing from one city to another becomes (n-2). Hence, the answer is n(n-2), which makes A an answer choice.   n(n-2)
<result>E</result>
There are n cities. What is the number of airlines that connected 3 different cities (airline from city A to city B is different with airline from city B to city A)?