My DD does the AoPS challenge problems in the book, Alcumus and the ones from the class.

IHO, the Alcumus ones are the easiest, the book ones sometimes make her stop and think but the hand graded one from the class almost always makes her stop and think.

Also, be sure to spend the extra money on the solutions manual as sometimes they reveal neat alternate ways of arriving at the same answer on the book problems.

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