A mechanical system comprises three subsystems in series with reliabilities of 98%, 92%, and 87%. What is the overall reliability of the system?

The overall reliability of the system is found to be 0.784 or 78.4%.

Explanation:

Since, the system has three subsystems in series with following reliabilities:

Reliability of 1st system = R1 = 98% = 0.98

Reliability of 2nd system = R2 = 92% = 0.92

Reliability of 3rd system = R3 = 87% = 0.87

Thus, the overall reliability for series configuration is given by the following formula:

Overall Reliability = (Reliability of 1st system) (Reliability of 2nd System) (Reliability of 3rd System)

Overall Reliability = (0.98) (0.92) (0.87)

Overall Reliability = 0.784

Overall Reliability = 78.4%