22) A

PSA
Amount of false positives = 10% x 74% = 0.1 x 0.74 = 0.074
Amount of false negatives = 90% x 0.8% = 0.9 x 0.008 = 0.0072

DRE
Amount of false positives = (85 ÷ 1000) x 100 = 8.5% = 0.085
Amount of false negatives = (16 ÷ 1000) x 100 = 1.6% = 0.016

So PSA gives fewer false positives and fewer false negatives than DRE. So 1 is correct and A is the answer.

Leave a Reply