My favorite is the 50% test case. If you flip a coin as a test and ascribe heads to true, 50% of the time it will describe what's happening accurately. So if y

My favorite is the 50% test case. If you flip a coin as a test and ascribe heads to true, 50% of the time it will describe what's happening accurately. So if you want to know "Has the Sun exploded?" you can flip a coin, assign heads to "Yes the Sun has exploded", and 50% of the time it will be correct. You flip a coin, you get heads. You decide to flip the coin again, and you get heads again! What are the odds the Sun has exploded?