Question

Cellphones that need to be repaired can only have software or hardware problems. 15 percent of cellphones sent to a repair shop are actually due software problems. If the cellphone actually has a software problem, a technician diagnoses it as a hardware problem 60 percent of the time. On the other hand, he diagnoses a hardware problem as a software problem 10 percent of the time. What is the probability that the cellphone actually has a hardware problem given that it was diagnosed as having a hardware problem?

Answer 1

I would first use a tree to describe the probabilities