If your 2 of 3 system is working, we must be in one of the following cases:
where G=good (working machine), and B=bad. Isn't the probability that any particular machine is working then 3 of 4?
An Engineering system consisting of n components is said to be k-out-of-n system if and only if atleast k of the n components function. Suppose that all components function independently of each other with the probability . Find the conditional probability that component 1 is working given that the system funstions, when k=2 and n=3.
(Punctuation in the wrong place can completely change the meaning of something ....)