Question

A victim of a street attack needs blood urgently and will die if she does not receive A Rh-negative blood within 8 minutes. Due to time constraints it takes 2 minutes to type a prospective donor’s blood and it takes another 2 minutes to complete the transfer of blood. That means that a useful donor must be found within 3 typings of donors. 30% of the untyped donors have type A Rh-negative blood. The victim will be saved if only one blood-typing kit is available. The kit is reusable, but can process only one donor at a time. The interest is in the probability that the victim will be saved. a) Name and write down the appropriate probability mass distribution function. b) Calculate the probability that the victim will be saved.

Answer 1