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**mathsandphysics** So P(C) = P($\displaystyle A$ n $\displaystyle B^c$) U P($\displaystyle B$ n $\displaystyle A^c$) would be the expression for C in terms of unions, intersections and complements of A and B.

How would I use this to derive an expression for P(C) in terms of P(A), P(B) and P(AnB).

Would it be like this?

P(C) = ( P(A) - P(A n B) ) u ( P(B) - P(A n B))

This is the question:

(c) Using result (b) derive an expression for P(C) in terms of P(A), P(B) and P(A nB). Give a detailed proof of the result.