Are you ill? (Posted on 2005-01-03)

	Submitted by e.g.
Rating: 3.7500 (4 votes)
Solution:	(Hide)
For the first test, 1% of the 99% of sane people get a (wrong) POSITIVE, as do 99% of the 1% ill people, so the chances of the result being correct are 50%-50%. After the second test, odds change to 99%-1%, so you are wrong 1 out of 100 times; after the third, 99.9898798%-0.010202%, so you are wrong 1 out of 9802 times, and after the fourth, you'd be wrong 1 out of 970,300 times, close enough to 1 million. By the way, three more tests would make your chances of being wrong 1 in 96 million, 1 in 9.5 billion, and 1 in 941 billion.

	Subject	Author	Date
	Puzzle Thoughts	K Sengupta	2023-04-30 22:52:11
	re: Correct Solution (for real)	Marc	2005-10-19 23:10:44
	Correct Solution.	A	2005-03-06 06:30:10
	Implications to our justice system	ajosin	2005-02-28 14:46:13
	re: Combined probabilities	Kyle	2005-01-07 15:37:44
	re: Combined probabilities	DJ	2005-01-07 12:51:58
	Combined probabilities	François	2005-01-06 17:16:22
	perplexus in the news	Penny	2005-01-04 02:34:16
	re(5): solution	Larry	2005-01-03 22:39:13
	re(4): solution	Penny	2005-01-03 21:23:49
	re(3): solution	Kyle	2005-01-03 21:15:43
	re(2): solution	Larry	2005-01-03 20:37:44
	re: This is a lousy example, but...	Eric	2005-01-03 20:25:07
	This is a lousy example, but...	Penny	2005-01-03 20:08:16
	re(2): solution	Eric	2005-01-03 20:05:06
	re: solution	Penny	2005-01-03 18:26:15
	solution	Charlie	2005-01-03 18:01:27
	Is your terminology correct ?	Penny	2005-01-03 17:40:33
	Meaning?	Angela	2005-01-03 17:28:48