Question:
If A and B are two mutually exclusive events such that P(A) = (1/2) and P(B) = (1/3), find P(A or B).
Solution:
Given : A and B are mutually exclusive events
$P(A)=\frac{1}{2}, P(B)=\frac{1}{3}$
To find : $\mathrm{P}(\mathrm{A}$ or $\mathrm{B})$
Formula used: $P(A$ or $B)=P(A)+P(B)-P(A$ and $B)$
For mutually exclusive events $A$ and $B, P(A$ and $B)=0$
Substituting in the above formula we qet.
$\mathrm{P}(\mathrm{A}$ or $\mathrm{B})=\frac{\frac{1}{2}}{2}+\frac{1}{3}-0$
$\mathrm{P}(\mathrm{A}$ or $\mathrm{B})=\frac{5}{6}$
$\mathrm{P}(\mathrm{A}$ or $\mathrm{B})=\frac{5}{6}$