Question

for a parallel structure of identical components, the system can succeed if at least 1 of the components succeeds. Assume that components fail independently of each other and that each component has a 0.19 probability of failure.
A) unusual to see 1 component fail?
B) unusual to see 2 components fail?
C)

Answer 1

depends what you mean by "unusual"

prob that 1 will fail = C(2,1)(.19)(.81) = .3078

prob that 2 will fail = ...... you try it, let me know how you did it