Question:
Given $P(A)=\frac{3}{5}$ and $P(B)=\frac{1}{5} .$ Find $P(A$ or $B)$, if $A$ and $B$ are mutually exclusive events.
Solution:
Here, $P(A)=\frac{3}{5}, P(B)=\frac{1}{5}$
For mutually exclusive events A and B,
P(A or B) = P(A) + P(B)
$\therefore P(A$ or $B)=\frac{3}{5}+\frac{1}{5}=\frac{4}{5}$