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 they were to connect an identical,backup gyroscope with a perfectly reliable switch to the primary gyroscope,what would be the reliability of the gyroscope function during a launch?
A)0.3
B)0.504
C)0.7
D)0.889
E)0.91

Question

Quizplus · Accepted Answer

The primary gyroscope has a failure rate of 0.3, so its reliability is 0.7. With a backup gyroscope, the system fails only if both gyroscopes fail, which is 0.3 * 0.3 = 0.09. Therefore, the reliability is 1 - 0.09 = 0.91.

The Chief of the Design Team for a New Missile