The probability of an adult to be infected with a certain virus is 0.003. In a test for the virus, blood sample from 15 people are combined. The combined sample will show positive if one or more of the 15 samples show positive for the virus. a) Let X = number of blood sample showing positive out of 15 blood sample be modelled by binomial distribution? Explain. What is n, p ? b) Find the probability that the combined sample of 15 blood sample (if one or more show positive) will show positive. c) Is it unlikely for the combined sample to show positive? Explain.