50 por 15 (Argentina)

Cincuenta × Quince, commonly called 50x15, originally called ¿Quién quiere ser millonario?, is the Argentinian version of Who Wants to Be a Millionaire?. Originally aired from 2000 until 2003 on El Trece, then revived from 2019 until 2020 on Telefe, the show was brought back as an El 37 primetime show.

Format
A group of ten contestants on each episode play a preliminary round called "Fastest Finger First". All are given a question by the host and four answers which must be placed within a particular order. If any contestants are visually impaired, the host reads the question and four choices all at once, then repeats the choices after the music for the round begins. The contestant who answers correctly in the fastest time goes on to play the main game. In the event that no one gets the question right, another question is given; if two or more contestants answer correctly but with the same time, they are given a tie-breaker to determine who will move on. This round is only used when a new contestant is being chosen to play the main round, and can be played more than once in an episode among those remaining within the group seeking to play the main game. In celebrity editions, and on civilian editions during the Telefe era, the round is not used; contestants automatically take part in the main game. For the El 37 revival, Fastest Finger First was reintroduced, but with six contestants, not ten.

Once a contestant enters the main game, they are asked fifteen increasingly difficult general knowledge questions by the host. Each features four possible answers, to which the contestant must give the correct answer. Doing so wins them a certain amount of money, with tackling more difficult questions increasing their prize fund. During their game, the player has a set of lifelines that they may use only once to help them with a question, as well as two "safety nets" – if a contestant gets a question wrong, but had reached a designated cash value during their game, they will leave with that amount as their prize. While the first few questions are generally easy, subsequent ones might prompt the host to ask if the answer they gave is their "final answer" – if it is, then it is locked in and cannot be changed. If a contestant feels unsure about an answer and does not wish to play on, they can walk away with the money they have won, to which the host will ask them to confirm this as their final decision; in such cases, the host will usually ask them to state what answer they would have gone for, and reveal if it would have been correct or incorrect. In the El 37 revival, the second safety net can be set at anywhere from $50.000 to $25.000.000, but cannot be moved.