Soccer tournament
Source: Cono Sur 2003 #1
November 18, 2015
algebracono sur
Problem Statement
In a soccer tournament between four teams, , , , and , each team plays each of the others exactly once.
a) Decide if, at the end of the tournament, it is possible for the quantities of goals scored and goals allowed for each team to be as follows:
\begin{tabular}{ c|c|c|c|c }
{} & A & B & C & D \\
\hline
Goals scored & 1 & 3 & 6 & 7 \\
\hline
Goals allowed & 4 & 4 & 4 & 5 \\
\end{tabular}
If the answer is yes, give an example for the results of the six games; in the contrary, justify your answer.
b) Decide if, at the end of the tournament, it is possible for the quantities of goals scored and goals allowed for each team to be as follows:
\begin{tabular}{ c|c|c|c|c }
{} & A & B & C & D \\
\hline
Goals scored & 1 & 3 & 6 & 13 \\
\hline
Goals allowed & 4 & 4 & 4 & 11 \\
\end{tabular}
If the answer is yes, give an example for the results of the six games; in the contrary, justify your answer.