A plane goes missing. According to air trac control, the probability that it has gone missing in region A is 0.2 and in region B is 0.6. From knowledge of these regions, it is known that if a plane goes missing in region A, the probability that it will be found is 0.7, while if a plane goes missing in region B, the probability of it being found is 0.6.
Using probability notation, answer the following questions.
(a). What is the probability that the plane did not go down in either region A or B? Justify your answer.
(b). If the probability of the plane being found if it goes down outside regions A or B is 0.1, what is the total probability of the plane not being found at all?
(c). If the plane isn't found, what is the probability it went down in region A?
(d). If two planes go missing independently, what is the probability that they are both found?