Deadly Disease

Topic: Probability

Difficulty: 6/10

 

 

 

Hint in 3…..

 

2………

 

1………

 

What is 1% of 1000 people?

 

 

Solution in 3…..

 

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1………

 

 

FULL SOLUTION

Step 1: Out of 1000 people, 10 of them (1%) would be a false positive and only 1 would be actually infected.

Step 2: Only 1 out of the 11 people tested positive is infected.

Step 3: The chances of you having it if you were to be tested positive is 1/11 = 9.1%

 

Bonus Content: The test is 99% accurate, but a 1% error is huge when dealing with large populations. Would you pay for an expensive treatment knowing that you have a 9% chance of actually having the disease?