probability

Consider a disease whose presence can be identi ed by carrying out a blood test. Let p denote the probability that a randomly selected individual has the disease. Suppose n individuals are inde- pendently selected for testing. One way to proceed is to carry out a separate test on each of the n blood samples. A potentially more economical approach, group testing, was introduced during World War II to identify syphilitic men among army inductees. First, take a part of each blood sample, combine these specimens, and carry out a single test. If no