Non-stop Flight

A mathematician was flying non-stop from Edmonton to Frankfurt with AirTransat. The scheduled flying time was nine hours.

Some time after taking off, the pilot announced that one engine had to be turned off due to mechanical failure. "Don't worry, we're safe," he assured the passengers. "The only noticeable effect this will have for us is that our total flying time will be ten hours instead of nine."

A few hours into the flight, the pilot informed the passengers that another engine had to be turned off due to mechanical failure. "But don't worry," he added. "We're still safe. Only our flying time will go up to twelve hours."

Some time later, a third engine failed and had to be turned off. The pilot came over the intercom with the news. "Don't worry," he once again stated, "Even with one engine, we're still perfectly safe. It just means that it will now take sixteen hours for this plane to arrive in Frankfurt."

The mathematician turned to a fellow passenger and remarked, "If the last engine breaks down, we'll be in the air for twenty-four hours altogether!"