Answer:
0.02 or 2%
Step-by-step explanation:
The probability that test A is negative if the illegal drug has been used (P(A|N)) is 0.1 while the probability that test B is negative if the illegal drug has been used (P(B|N)) is 0.2.
Therefore, the probability that neither test is positive if the illegal drug has been used is:
[tex]P(A \cap B|N) = P(A|N)* P(B|N) = 0.1 *0.2\\P(A \cap B|N) = 0.02[/tex]
There is a 0.02 or 2% probability that neither test is positive if the illegal drug has been used.
Answer: 0.02
Step-by-step explanation:
For test A:
The probability of not being positive if the illegal drug has been used is = 1 - 0.9 = 0.1
For test B:
The probability of not being positive if the illegal drug has been used is= 1 - 0.8 = 0.2
Therefore the probability of neither A or B being positive if the illegal drug has been used is
= Pa×Pb = 0.1×0.2 = 0.02
