Here is problem.
Mr.X manages two auto parts stores,because he orders parts for both stores from the same supplier, he finds that if he runs out of a particular part at east store, he is usually out of the same part at the west store. Specifically 72% of the time that east store ran out of the KG—3 muffer so did the west store. If the probability of running out of this muffer at east store is 0.2 what is the probability of being out of the muffer at both the stores?
What information is needed to decide the probability of being out of the muffer at west store?