4. Two mark example problem III

If $A$ and $B$ are two events such that $P(A) = \frac{1}{4}$, $P(B) = \frac{1}{2}$ and $P(A \ \text{and} \ B) = \frac{1}{8}$, find (i) $P(A \ \text{or} \ B)$ (ii) $P(\text{not} \ A \text{and not} \ B)$.

 

Answer:

 

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

 

(ii) $P(\text{not} \ A \text{and not} \ B) =$ $\frac{i}{i}$