A set of football matches is to be organized in a "round-robin" fashion, i.e., every
participating team plays a match against every other team once and only once. If 6
matches are totally played, how many teams participated? Choose the correct choice from the following choices
A) 4	B) 5	C) 6	D) 7	E) 8
2 ways to solve this problem..   summation(x)=n(n-1)/2   n(n-1)/2=6;   n^2-n-12=0   4ns : 4   4NSWER:4
<result>A</result>
A set of football matches is to be organized in a "round-robin" fashion, i.e., every
participating team plays a match against every other team once and only once. If 6
matches are totally played, how many teams participated?