The reliability of a COVID PCR test is specified as follows
Of people having COVID, 90% of the test detects the disease but 10% goes undetected. Of people free of COVID, 99% of the test is judged COVID negative but 1% are diagnosed as showing COVID positive. From a large population of which only 0.1% have COVID, one person is selected at random, given the COVID PCR test, and the pathologist reports him/her as COVID positive.

Based on the above information, answer the following
What is the probability that the ‘person selected will be diagnosed as COVID positive’?

Options

A. 0.1089
B. 0.01089
C. 0.0189
D. 0.189

Answer

B