In my main technical blog I have suggested an elegant formula for calculating cluster availability. Let me interpret.
You have one woman, and you know that she is faithful to you 90% of the time. I.e., she is cheating on you 10% of the time… That’s upsetting. You get yourself another woman, exactly like the first one. So, when the first one is cheating, the second one is with you. According to my availability formula 99% of the time either both or just one of the women is available to you. But during 1% of the time both of them are cheating! That is still upsetting… Get a third woman!
And now a tricky question – what percentage of the time will you be spending alone in that case?
(Hint: just solve the following Trubin’s equation…)