Pandemic
In Mathland, there is a chance that any given person might have the deadly 'Super Flu'. Thankfully, it is possible test for the presence of the disease. If a person has the flu, a positive result is certain. However, there is a chance of the test giving a false positive. Alice takes the test, and receives a positive result. Worried, she takes another test, and receives another positive result. Which is true of the following statements?
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1 solution
The chance of recieving two false positives in a row is 1 0 0 1 2 = 1 0 0 0 0 1 . We can see that 1 0 0 0 0 1 = 2 ∗ 2 0 0 0 0 1 , so it is twice as likely that Alice does not have the flu.