Devices are made up of five independent components. A given device operates if at least four of its five components are active. Each component operates with probability 0.95. We receive a very large batch of these devices. We inspect the devices, taken at random and with replacement, one at a time until a first device that does not operate has been obtained.
- What is the probability that a device taken at random operates?
- What is the expected value of the number of devices that will have to be inspected?