The main story of Call of Duty: Modern Warfare 3 lasts around five hours, according to HowLongToBeat. However, you have to be solely focused on the story or just really good to beat it in that time. If you go for some of the achievements as well, then it will take around seven hours.

Modern Warfare 3's campaign should take you roughly 4-7 hours to complete. This is based on our run through the single-player component on Regular difficulty, as well as on community sentiment and reports.

You will never win any money. They will either reset your progress before you can cash out, or just not let you cash out at all.

The game does pay out, as contestants can win varying amounts of money depending on where their chips land. However, the game is based on chance, so there is no guaranteed payout for any specific contestant. The legitimacy of Plinko and similar games that promise real money payouts is often debated.