How many cards are in each of the three envelopes?:
The 1st envelope has two more bills than half the number that are in the 2nd envelope.
If you double the number of notes in the 3rd envelope, it would have the same number as the 1st and 2nd together.
The 3rd envelope has more than the 1st, but fewer than the 2nd.
Answer: The two envelopes problem, also known as the exchange paradox, is a brain teaser, puzzle, or paradox in logic, probability, and recreational mathematics.
