- Home
- Standard 11
- Mathematics
14.Probability
medium
In two events $P(A \cup B) = 5/6$, $P({A^c}) = 5/6$, $P(B) = 2/3,$ then $A$ and $B$ are
A
Independent
B
Mutually exclusive
C
Mutually exhaustive
D
Dependent
Solution
(b) $P(A{^c}) = 1 – P(A)$ $ \Rightarrow $ $P(A) = \frac{1}{6}$
Now $P(A \cup B) = P(A) + P(B) – P(A \cap B)$
$⇒ \frac{5}{6} = \frac{1}{6} + \frac{2}{3} – P(A \cap B)$ ==> $P(A \cap B) = 0$
Hence, events $A$ and $B$ are mutually exclusive.
Standard 11
Mathematics