In a certain match all the teams were to play with each other. If there are 12 teams, how many matches will have to be played?  Choose the correct choice from the following answers:	A) 40	B) 45	C) 66	D) 90	E) None of the above
12c2   =66   ANSWER:66
<result>C</result>
In a certain match all the teams were to play with each other. If there are 12 teams, how many matches will have to be played?