IB μαθηματικά SL – Probability

Probability – IB Mathematics SL – IB maths SL

Find the probability \(P(A \cap B’)\) if A and B are two events such that \(P(A)=0.6\), \(P(B)=0.2\) and \(P(A \cup B)=0.7\).

Solution

We know that

\(P(A \cup B)=P(A)+P(B)-P(A \cap B) \Rightarrow \) \(P(A \cap B)=0.6+0.2-0.7=0.1 \)

Finally, we have

\(P(A \cap B’)=P(A)-P(A \cap B) =0.6-0.1=0.5 \)