There are a total of 11 students in Mr. Michael's gym class. Over the course of a badminton unit, each of the 11 students will compete exactly once against every other student in the class. How many total games of badminton will be played?
Choose the correct choice from the following answers.
A) 58 B) 51 C) 52 D) 55 E) 59
there are 11 students , if each play with all other members .   then total games can be calculated as 10+9....+1 = 55.   alternate approach is to choose 2 distinct out of 11 = 11c2 = 55   Answer is 55.
<result>D</result>
There are a total of 11 students in Mr. Michael's gym class. Over the course of a badminton unit, each of the 11 students will compete exactly once against every other student in the class. How many total games of badminton will be played?