Answer for the Previous Riddle

WARNING: Just in case you stumble upon the answer here first, please read the previous post before continuing.

Full answer after the jump.

The answer is that there is no such thing as a missing dime in this riddle. The reader is misled by the presumptive nature of the question. There is no reason why the amount paid by the three men, $2.70, should add up to $3.00 if you add it to the 20 cents the waiter put in his pocket. That 20 cents came out of the $2.70 they paid. So the correct calculation is that the bill of $2.50 plus the 20 cents taken by the waiter should add up to the $2.70 (3 x $0.90) that the men paid. Nothing is missing.