Five dollar bill with the president printed on both sides?

Answer 1

If the image is in reverse, you could have what's called an offset error. That happens when a sheet of paper gets stuck and doesn't enter the printing press. The inked plates transfer their image to the impression cylinder and the backs of the next few sheets get a mirror-image of the bill's front.

Approximate value range: $200 - $300

Answer 2

A five dollar bill with the president printed on both sides could be considered a counterfeit bill. Legitimate US currency has different portraits on the front and back. If you come across such a bill, you should report it to the authorities or your local bank.