A machine has 9 identical components that function independently. The probability that a component will fail is 0.2. The machine will stop working if 1 or 2 components fail. Find the probability that the machine will be fail?

Answer 1

Either-or probabilities are found by adding the individual probabilities.

If the events are independent, the probability of both/all events occurring is determined by multiplying the probabilities of the individual events.

P(1 fail) = .2 * .98^8 = ?

P(2 fail) = .2^2 * .98^7 = ?

Answer 2

Sorry, I gave you the answer to not failing. Subtract the answer to above from 1.00.

Answer 3

Ignore my second post.