Halloween is scary, what with all the costumes and the ghosts and the amount of sugar in candy corn. Do you know what else is scary? Algebra, what with all the numbers and the rules and the math. So a ...

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An amusing parlor trick is performed as follows. Ask spectator A to jot down any three-digit number and then to repeat the digits in the same order to make a six-digit number (e.g., 394,394). With ...