This is a solution book for 1990 - 2000 Mathcounts National Competition Sprint and Target round problems. Jane Chen is the author of the book "The Most Challenging MATHCOUNTS(R) Problems Solved"- 2001-2010 National Mathcounts Solutions" officially published by Mathcounts.org. For 1990-2000 Mathcounts National Team Round solutions: https: //www.amazon.com/dp/1543272304 2000-2010 Mathcounts National Team Round solutions: https: //www.amazon.com/dp/1544764421