An airplane was flying from LA to New York.
About an hour into the flight, the pilot announced, "We have lost an engine, but don't worry, there are three left.
However, instead of 5 hours it will take 7 hours to get to New York." A little later, the pilot announced, "A second engine failed, but we still have two left.
However, it will take 10 hours to get to New York." Somewhat later, the pilot again came on the intercom and announced, "A third engine had died.
Never fear, because the plane can fly on a single engine.
However, it will now take 18 hours to get to new York." At this point, one passenger said, "Gee, I hope we don't lose that last engine, or we'll be up here forever!"