Discussion:
Q: The camera department of a large department store sells three different brands of cameras: Proxima, Yakima, and Tetron. Approximately 60% of the cameras sold are Yakimas with Tetrons accounting for 30% of sales and Proxima the remaining 10%. Store records show that approximately ¼ of those who purchase a Yakima return within one year to purchase accessories for their camera. The corresponding figures for the other two are: Tetron, 1/5; and Proxima, 3/5. If a person is known to have purchased an accessory within a year of the purchase of a camera, what is the probability the person purchased a Yakima?