There are n cities. What is the number of airlines that connected 4 different cities (airline from ...
There are n cities. What is the number of airlines that connected 4 different cities (airline from city A to city B is different with airline from city B to city A)?
Answer/Solution
n(n-3)
Steps/Work
First of all, the possible number of airlines is n. Then, the possible number of airlines departing from one city to another becomes (n-3). Hence, the answer is n(n-3), which makes A an answer choice.
B
B