statistics and probability

2. In a small isolated town in Northern Saskatchewan, 90% of the Cola consumed by the townspeople is purchased from the general store, while the rest is purchased from other vendors. Records show 60% of all the bottles sold are returned. Accordingly to a special study, a bottle purchased at the General store is four times as likely to be returned as a bottle purchased elsewhere. a) Calculate the probability that a person buying a bottle of Cola from the general store will return by empty bottle. b) If a Cola bottle is found lying in the street What is the probability that it was not purchased at the general store