An alarm system may fail safe (false alarm) or may fail to danger (failure on demand). If the fail-safe failure rate is a constant 0.00034 failure per operating hour and the fail-to-danger rate is a constant 0.000021 failure per operating hour, what is the design life of the alarm if an operating reliability of 0.99 is desired? What is the probability of fail-to-danger over 1000 operating hours?