Question

If $A$ and $B$ are mutually exclusive events and if $P(B)=\frac{1}{3}$, $P(A\cup B)=\frac{13}{21}$, then $P(A)$ is equal to

• A. 1 / 7
• B. 4 / 7
• C. 2 / 7
• D. 5 / 7

Answer 1

Answer: (C)

For mutually exclusive events
$P(A\cup B)=P(A)+P(B)$
$\Rightarrow P(A)=\frac{2}{7}$