indeed. I am not a physics guy. So i just say the probability of an MCAS failure is p; probability of flight without failure is (1-p).
So, probability of n flights without failure (1-p)**n.
Just for the record. MCAS did not fail in these incidents (with available information so far).
The culprit was a SINGLE AoA vane that sent erroneous data to the MCAS. If the vane had a duplicate then MCAS would not be seen as the villain it currently is.
Imagine if a single vane activated a stick pusher at low altitude. Would you blame the stick push system or the design of a single vane having so much authority?