The Ready Light Company produces a flashlight which is perfectly reliable except for two components: the battery, which has a random failure rate of one in every five hours of operation; and the light bulb, which has a random failure rate of three in every ten hours.
If the company includes both a backup light bulb and a backup battery with each flashlight, what is the probability that the flashlight will perform reliably for one hour (excluding replacement time)?
1. a. 0.6720
2. b. 0.7280
3. c. 0.8736
4. d. 0.9100
5. e. 0.9600