According to the generally question for conditional probability if P (AnB) = 5/7 and P (B) = 7/8 what is P (A|B) ?

Hi!

P (A|B) means the probability A will happen given B has happened. P (AnB) is the probability both will happen, and P (B) is the probability B will happen.

You can figure out a formula from that, but here's the generally accepted one:

P (A|B) = P (AnB) / P (B)

P (AnB) = 5/7

P (B) = 7/8

Substitute values in:

P (A|B) = 5/7 / 7/8

P (A|B) = 5/7 * 8/7

P (A|B) = 40/49