Probability Unions: Solving Problems

[cue928]

Have a problem that I've worked through, would appreciate any feedback on it to tell if I'm doing it correctly:

Say the probability of success is .95. Two different actors, acting independently:
1. Probability that both actors are successful: I had P(A intersect B) = P(A) * P(B) = (.95)*(.95) = .9025

2. Probability that neither actor is successful? Was a little confused on this one, but I thought it would be P(A U B)'. In (3), I'd calculated the P(A U B) to be .9975, so 1-.9975 = .0025

3. Probability that either actor is successful? I used P(A U B) = P(A) + P(B) - P(A intersect B) = .9975

thank you much.

 

[daveb]

Looks pretty good to me!

 

[micromass]

Looks ok!

May I suggest another method for (2)?? The chance that an auther is not successful is 0.05. so the chance that neither author iss successful is 0.05*0.05 by independence.