Thread: Probability problem.

Please, help me! ( I think my difficulties with it because of my poor English a cause- result? or intersection of 2 events? )
Ann estimates that there is a 60% chance that she will get a raise if she asks her boss.
a) If there is a 40% chance that Ann will, in fact, ask her boss for a raise, what is the probability that she will get a raise because she asked a one?
b) If there is a 10% chance that Ann's boss will give her a raise before she even asks for one, what is the probability that Ann will get a raise without asking for one?

I see that it's about conditional probability, but can't get the answer.
Thank you!

My guess is that

Prob(raise|ask)=.6*.4=.24

Prob(raise|not ask)=.10

Why is Prob(raise|not ask)=.10 ?

Part 2 of your original post says it!

Originally Posted by Romanka

Ann estimates that there is a 60% chance that she will get a raise if she asks her boss.
a) If there is a 40% chance that Ann will, in fact, ask her boss for a raise, what is the probability that she will get a raise because she asked a one?
b) If there is a 10% chance that Ann's boss will give her a raise before she even asks for one, what is the probability that Ann will get a raise without asking for one?
I see that it's about conditional probability, but can't get the answer.

Frankly I doubt you have received sound replies yet.
We have no way to know that the events are independent!
If they are independent, then conditional probability is a moot question.
Basically, I find this a deeply flawed question. It may be a translation problem.
We need more clarification on what the question actually says.

Well they are dependent by definition, whether or not she asks for the raise affects the probability that she gets one, according to the given values. I do agree that the wording is misleading so you might disagree with this..

The "because she asked for one" can be interpreted as, "what is the probability that she asked for a raise AND that she received one." In this case, it would be P(ask)*P(get raise|ask), where. So it would be 0.4 * 0.6 = 0.24.

The second question is worded confusingly, because it says "before she even asks." This implies that she might be considering asking for a raise but her boss might give her one before she even had the chance to ask.

If we interpret it literally... the answer is simply 10%.. the question is basically a rephrase of the very first statement in that problem.. "there is a 10% chance she will get a raise before she asks for one".. this implies that the chance that she does get a raise without asking for one is indeed simply 10%.. but then, it might be a problem with the wording.

That is the original question from the test (not my translation). I thought I can't clarify it for myself and understand because of my English, but you are agree with me- it's "a deeply flawed question" ((

Originally Posted by SworD

it might be a problem with the wording.

the only explanation that I have

Well I interpreted the wording literally and gave you answers, is there any way you can verify?

Another interpretation of the problem can result in:
a=ask
na=not ask
r=raise

Thank you, all!!!