I'm braindead right now, so any help would be greaatt..
Girl has 3 exams that she will take in order, if she fails any exam she's not allowed to go on. Prob that she passes the first exam is .9. If she passes the 1st exam, then the conditional probability that she passes the second one is .8, and if she passes both the first and 2nd exam, then the conditional prob that she passes on the 3rd exam is .7.
a) What is the prob that she passes all three?
Do you just multiply all of them together? That seems like it'd be too easy..
b) Given that she did not pass all 3, what is the conditional prob that she failed the 2nd exam?
Girl has 3 exams that she will take in order, if she fails any exam she's not allowed to go on. Prob that she passes the first exam is .9. If she passes the 1st exam, then the conditional probability that she passes the second one is .8, and if she passes both the first and 2nd exam, then the conditional prob that she passes on the 3rd exam is .7.
a) What is the prob that she passes all three?
Do you just multiply all of them together? That seems like it'd be too easy..
b) Given that she did not pass all 3, what is the conditional prob that she failed the 2nd exam?