1. FAST and SLOW
2. Door B has the correct sign on it; Door D conceals the prize
3. 5 jars and 16 pencils
4. 7 jars and 45 pencils
5. 13 ways
6. The years quoted are BC, Not AD
7. Eight cubes will have three painted faces; twenty four cubes will have two painted faces; twenty four cubes will have one painted face; eight cubes will have no painted faces
8. Left to right: jack of clubs, jack of diamonds, queen of diamonds.
9. $8.60
10. 20 possible opening moves. (Each pawn may advance either one or two squares; each knight may make two possible opening moves)