Friday Quiz. What is the unconditional mathematical expected duration between departure and time to destination between Kuala Lumpur and Beijing? How about a flight between Rio de Janeiro and Paris?

ANSWER: Infinite. A very tiny probability of crash makes the unconditional expectation infinite.

All other answers with finite duration are conditional on the plane eventually making it to destination.

via Friday Quiz. What is the unconditional… – Nassim Nicholas Taleb.