Question

According to the general equation for conditional probability, if P(An B)=4/7 and P(B)= 7/8, what is P(A|B)

Answer 1

The rule for conditional probability states that

$P(A|B) = \dfrac{P(A\cap B)}{P(B)}$

Since we're given both numerator and denominator, we only need to plug the values in:

$P(A|B) = \dfrac{\frac{4}{7}}{\frac{7}{8}} = \dfrac{4}{7}\cdot \dfrac{8}{7} = \dfrac{32}{49}$