Answer: Hello! if you have 150 people and you want to see how many two-person conversations are, then you need to see the combinatory between 150 and 2.
The combinatory between two numbers A and B is [tex]\frac{A!}{B1*(A - B)!}[/tex] Where the combinatory between two numbers is all the possible combinations of A into groups of size B.
Then for 150 and 2, we have [tex]\frac{150!}{2!*(148!)} = 150*149/2 = 11175 \\[/tex]
So you have 11175 possible conversations.
