Mutually Exclusive Events – The Addition Rule (Leaving Cert Mathematics): Quizzes

They cannot occur simultaneously

$P(A \text{ or } B) = P(A) + P(B)$

The OR rule

$\frac{5}{7}$

To avoid counting overlaps twice

$P(A \text{ or } B) = P(A) + P(B) - P(A \text{ and } B)$

Yes, 3 is odd so cannot be even

No, 6 is both even and > 4

No, 2 is both prime and even

Can these events happen simultaneously?

$\frac{14}{30}$

Double counting the intersection