There are a cities. What is the number of airlines that connected 2 different cities (airline from city A to city B is different with airline from city B to city A)? Answers
A) n(n-1)
B) n(n+1)
C) a(a-1)
D) n(n+1)/2
E) n2
First of all, the possible number of airlines is a. Then, the possible number of airlines departing from one city to another becomes (a-1). Hence, the answer is a(a-1), which makes a(a-1)
<result>C</result>
There are a cities. What is the number of airlines that connected 2 different cities (airline from city A to city B is different with airline from city B to city A)?