Isn it unfair to allow schools and students to take the contests twice within two weeks time?
Not really. The contest problems for the last 53 years of high school contests are available in books, and in copies of old contests. The problems are basically the same from contest to contest, so there is plenty of common material to study. The addition of another 25 contest problems with two more weeks to study is not a significant advantage for any student. Furthermore, it is the philosophy and purpose of the AMC to encourage students to engage in significant mathematical problem solving. If we can do this by offering more contests, then we are better meeting our goal.
