Question

NEED AN EXPLANTION Six people participated in a checker tournament. Each participant played exactly three games with each of the other participants. How many games were played in all?

Answer 1

45

Explanation:

Solve the problem with just one round, then multiply by three:

1. Person 1 played against the other 5 people
2. Person 2 played against the other 4 people he hadn't played against
3. Person 3 played against the other 3 people he hadn't played against
4. Person 4 played against the other 2 people he hadn't played against
5. Person 5 played against the other 1 person he hadn't played against
6. Person 6 played againt the other 0 people as he had already played them
7. 5+4+3+2+1+0=15
8. 15•3=45