Question

Given, $P\left(A\right)=\frac{3}{5}$ and $P\left(B\right)=\frac{1}{5}$. Find $P\left(A\text{or}B\right)$, if $A$ and $B$ are mutually exclusive events.

Answer 1

Here $P\left(A\right)=\frac{3}{5}$, $P\left(B\right)=\frac{1}{5}$
For mutually exclusive events $A$ and $B$
P(A or B) $=P\left(A\right)+P\left(B\right)$
$\therefore P\left(AorB\right)=\frac{3}{5}+\frac{1}{5}=\frac{4}{5}$