← Paradoxes & riddles
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The False Positive Paradox
when a positive test is probably wrong
A rare disease affects 1 in 1,000 people. A test catches 99% of people who have it, and correctly clears 99% of people who don't. You test positive. How likely is it that you actually have the disease?
Source: A classic puzzle, retold by INFINITE SUM and fact-checked against our curated notes
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