# 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

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