This is a problem offered to our students this week in the monthly Florida Math league contest. Lots of schools across the state participate. Not many of our kids got it, but surely you are smarter that a high school student, right??
The Surfboard Store sells Special Surfboards that
are so carefully made that only 1 in 1 thousand
is bad. The store tests all Special Surfboards
using a test that is 99% accurate. If you buy
a Special Surfboard that tests bad, what is the
probability that it really is bad?
Think about it a while and put your answer in the comments here or at the forum where this is posted. (or you can message me if you're shy) I will try to explain the answer tomorrow.