Posted by Christina on .
If P(a)=1/5, P(A and B)= 1/8, what is P(b/a)
i don't get it is it the same way as finding p or b or is it something entirely different and how do you find it

Algebra 2 
Reiny,
I think you are dealing with "conditional probability"
usually written as P(B│A) and read as
"the probability of B given A"
P(B│A) = P(A and B)/P(A)
= (1/8) / (1/5)
= 5/8 
Algebra 2 
Christina,
so it would be division then i would have to cross multiply right??? by the way thank you...Alot!

Algebra 2 
Reiny,
You are dividing 2 fractions at the end
(1/8) / (1/5)
= (1/8) รท (1/5)
= (1/8)x(5/1)
= 5/8