201. A group of 100 patients is tested, ..-阿摩線上測驗
201. A group of 100 patients is tested, one patient at a time, for three risk factors for a certain
disease until either all patients have been tested or a patient tests positive for more than
one of these three risk factors. For each risk factor, a patient tests positive with
probability p, where 0 < p < 1. The outcomes of the tests across all patients and all risk
factors are mutually independent.
Determine an expression for the probability that exactly n patients are tested, where n is a
positive integer less than 100.
(A)
(B)
(C)
(D)
(E)