A Certain Product Is Comprised of Two Components: X and Y.Component

Short Answer

A certain product is comprised of two components: X and Y.Component X has a random failure rate of one in every ten years,while component Y's random failure rate is one in every five years.This product has a mean time to wear-out of eight years with a standard deviation of one year.What is the service life for this product which will provide a .5 probability of not failing within that amount of time? A .6915 probability? A .8413 probability? A .9332 probability?