# Thread: Probability_2

1. ## Probability_2

Can anyone help me with this task, please ?

2. Originally Posted by kochwow
Can anyone help me with this task, please ?
Those are completely straightforward problems.
So where are you having difficulties?
Do you know the rules and/or the definitions involved?

3. Originally Posted by Plato
Those are completely straightforward problems.
So where are you having difficulties?
Do you know the rules and/or the definitions involved?
I'm sure that for you they are completely straightforward and you do not have any problems with solving them. However, I posted it, simply because I don't understand it at all. What would be the point of posting thread which I can solve?
I don't know the rules, probability it's just one of those things that don't come into my head and I can't understand them...

I'm sorry if I've disappointed you by NOT KNOWING the answer for this completly straightforward problem.

4. O.K. then reply to this question. The answer is in your textbook.
You tell us what are the correct formulas (rules) for $P(A|B) = ?\;\& \;P(A \cup B) = ?$

I will give you some hints on part c).
$\left( {A^c \cap B^c } \right) = \left( {A \cup B} \right)^c \; \Rightarrow \;P\left( {A^c \cap B^c } \right) = 1 - P\left( {A \cup B} \right)$.