2007 Cayley Problem 21

In a soccer league with 6 teams (P, Q, R, S, T, W), each team must eventually play each other team exactly once. So far, P has played one match, Q has played 2 matches, R has played 3 matches, S has played 4 matches, and T has played 5 matches. How many matches has W played so far?

\textbf{(A)}\ 1\quad \textbf{(B)}\ 2\quad \textbf{(C)}\ 3\quad \textbf{(D)}\ 4\quad \textbf{(E)}\ 5

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Cayley contests here.