Find the probability of the following event :

$\displaystyle P(A \prime \cap C | B\prime )$

Attempt @ solution :

$\displaystyle P(A \prime \cap C | B\prime ) =\frac{P ( A \prime \cap C \cap B \prime)}{P(B \prime)}= \frac{P ( A \prime \cap C \cap B \prime)}{1-P(b)}$

I am stuck on how do deal with $\displaystyle P ( A \prime \cap C \cap B \prime)$ Is there a way l can simplify this thing ?