Question

Probability of occurrence of at least two of the three events occuring together

Answer 1

Answer:

Step-by-step explanation:

All events are independent.

Pr(A)=9/10

Pr(B)=9/10

Pr(C)=6/10

I'd like to use negation, to negate the possibility that event no event happen plus the probability that only one happens.

D=at least two events happen

Pr(D)=1−Pr(none happens)−Pr(exactly one happens)

Pr(D)=1−(1/10⋅1/10⋅4/10)−(1/10⋅6/10⋅1/10+9/10⋅1/10⋅4/10+9/10⋅1/10⋅4/10)=0.918

The answer seems a little larger, I can't convince myself that I'm right.