Shortly after starting the laundry, you realize that you cannot nd your iPhone 6 that contains your only complete set of contact info. When you retrieve the iPhone, you nd that it is inert. You take it to a service depot. If water did not get into the main memory chips, there is a 0.67 probability that they will be able to retrieve your data. If water did get into the memory chips, there is a 0.15 probability that they will be able to retrieve your data. Secret testing by Apple suggests that water gets into the memory chips of laundered iPhones in 4 out of every 10 cases.
(a) What is the probability that water got into the memory chips if you know that the info was saved?
(b) What is the probability that water didn't get into the memory chips if you nd that the data was lost?
(c) If you could persuade them to try retrieval a second time in the event of a failure, suppose that a second try would have a 0.67 probability of retrieval if the memory chips were dry and a 0.1 probability of retrieval if they were wet. What would be the probability that you could retrieve your data?