Question 157
Some seventh and eighth year students of a school participate in a ping-pong tournament, where each student plays against all the others exactly once receiving 1 by victory and 0 point by defeat. There are ten times more eighth graders than seventh graders. The total score of the eighth grade students is 4.5 times the total score of seventh grade students.
a) Check that in the tournament there are $k$ students, then the number of games is $\frac{k(k-1)}{2}$.
b) What is the sum of the scores obtained by all seventh graders?
a) Check that in the tournament there are $k$ students, then the number of games is $\frac{k(k-1)}{2}$.
b) What is the sum of the scores obtained by all seventh graders?