Question

In a football championship, there were played 153 matches. Every team played one match with each other. The number of teams participating in the championship is.

• A. 17
• B. 18
• C. 9
• D. 13

Answer 1

Answer: (B)

18

Answer 2

$nC_{2} = 153 \Rightarrow \frac{n(n - 1)}{2} = 153 \Rightarrow n = 18$.