Question

To determine whether or not they have a certain blood disease, 100 people are to have their blood tested. However, rather than testing each individual separately, it has been decided first to group the people in batches of 10. The blood samples of the 10 people in each batch will be pooled and analyzed together. If the test is negative, one test will suffice, else each of the ten people will be individually tested. Assuming the incidence of disease to be 1% for the population, find the expected number of tests required for each batch.

Answer 1

435227To determine whether or not they have a certain blood disease, 100 people are to have their blood tested. However, rather than testing each individual separately, it has been decided first to group the people in batches of 10. The blood samples of the 10 people in each batch will be pooled and analyzed together. If the test is negative, one test will suffice, else each of the ten people will be individually tested. Assuming the incidence of disease to be 1% for the population, find the expected number of tests required for each batch.