For a Rugby Union game, what's the smallest score that allows you to say that there must have been at least four (converted or not) tries?

"20" isn't the correct answer, because you could have managed it with two converted tries and two penalties. "21" isn´t it either, for three converted tries suffice, and "22" also doesn´t work, for you can manage it with less than 4 tries.

NB. The scoring is: 3 for a drop-goal or penalty kick. 5 for a try, and 7 for a converted try (A converted try is when a try has been scored, and the team that scored kicks the ball between the posts.)

The fact that 5 is congruent with -1 mod 3, and 7 is congruent with +1 mod 3 can be used to show that you never need more than ONE try, so the answer to the question is ¨You can never say there have been four tries."

Posted by Old Original Oskar! on 2006-04-24 08:59:01