How Do You Calculate Conditional Probability Using a Probability Tree?

[hasnain721]

conditional probability help please

Homework Statement

Hi there,
I am doing s1 for this jan and i am finding it very difficult to cope up. Especially for probability. I have a cgp buk but stil its not very gud at probability. Here is a question from my text buk which i cud not understand : -




Two events A and B are such that P(A) = 3/4 , P(B l A) = 1/5 and P(B' l A') = 4/7. By use of a probability tree or other wise find :


a) P(A and B)

b) P(B)

c) P(A l B)



In addition, can some 1 suggest a gud buk for probability please.

Homework Equations

P(B l A) = P(A intersection B) / P(A)

The Attempt at a Solution

I got 'a' right by multiplying 3/4 by 1/5


Plz reply
Thanks
Hasnain Mir Mohammed

 

[hasnain721]

i hav worked it out now...thanks.