Want to learn how to tackle those tough AMC/AIME/Olympiad algebra problems? Check out Art of Problem Solving's NEWIntermediate Algebra by Richard Rusczyk and Mathew Crawford. Over 1600 problems!
Want to learn how to tackle those tough AMC/AIME/Olympiad counting and probability problems? Check out Art of Problem Solving's NEWIntermediate Counting & Probability by David Patrick.