Persephone3: Riddle 2, I don't see the problem other than the math is wrong.
they paid $30 for pizza but the price was $25, supplying the $2 that the delivery boy stole that is 25+2 = $27 which is what they paid for, 3x9=27 not 29. I think you counted the 2 to many times. Accountants would go crazy over the math in that riddle, not a bad one tho.