Consider a reliability block diagram shown below: Assume that the units 1, 2 and 3 have constant failure rates A1 1.0, 12 1.5,and Az 2.0, respectively; that is, the time to failure for each component is an exponential random variable with the mean time to failure 1/11, 1/12 and 1/23, respectively: Determine the system reliability at time t 0.5. Answer with two decimal places_
Unit 1 (21
Unit 2 (12
Unit 3 (23)