what do you call a book that only contains questions and answers, no other stuff. Maybe "questionnaire" is one but I think questionnaires only contain questions.
Possible terms include:
- quiz book - Implies that it's a book containing quizzes or tests.
- workbook - Often accompanies a student textbook, and contains supplementary questions/problems to answer/solve.
- puzzle book - Contains a bunch of puzzle problems/questions for entertainment.
Informally, a "Q & A". Otherwise, I'd be inclined towards "catechism" as well, except for the religious connotations: http://www.merriam-webster.com/dictionary/catechism