The Chief of the Design Team for a New Missile

Multiple Choice

The chief of the design team for a new missile wants to know the reliability of its guidance system.This system is comprised of three components: a gyroscope,which has a random failure rate of 3 in every 10 launches; a computer,which has a random failure rate of 2 in every 10 launches; and a rocket motor,which has a random failure of 1 in every 10 launches.If the battery used to power the computer has a mean time to fail of 60 minutes with a standard deviation of 20 minutes,what is the probability that it will last for a launch of 30 minutes duration without failing?

A) 0.9332
B) 0.8664
C) 0.5668
D) 0.4332
E) 0.0668