1) If you ever come across a situation where components fail independently of each other and that each component has a 0.11 it won'be unsusual because such percent as 11% is quite frequent and common.
2) If two components fail, that will definitely be unusual as the percent greatly increases : 11%*11%=1,21% - it is not as common as in previous situation.
3) Here is the way how you can get the probability that a parallel structure with 2 identical components will succeed :
you have to take the obtained percent away from 100%
100-1,21=98,79
4) The number of components that will be needed in the structure so that the probability the system will succeed is greater than .9999 is being shown below:
[tex]12^n = .0001
n = 4.34[/tex]
then just round it up.
Do hope that will help you!
