A die marked $1,\,2,\,3$ in red and $4,\,5,\,6$ in green is tossed. Let $A$ be the event, $'$ the number is even,$'$ and $B$ be the event, 'the number is red'. Are $A$ and $B$ independent?
When a die is thrown, the sample space ( $S$ ) is
$\mathrm{S}=\{1,2,3,4,5,6\}$
Let $A:$ the number is even $=\{2,4,6\}$
$\Rightarrow P(A)=\frac{3}{6}=\frac{1}{2}$
$B:$ the number is red $=\{1,2,3\}$
$\Rightarrow P(B)=\frac{3}{6}=\frac{1}{2}$
$\therefore $ $A \cap B=\{2\}$
$P(A B)=P(A \cap B)=\frac{1}{6}$
$P(A) P(B)=\frac{1}{2} \times \frac{1}{2}=\frac{1}{4} \neq \frac{1}{6}$
$\Rightarrow $ $P(A) \cdot P(B) \neq P(A B)$
Therefore, $A$ bad $B$ are not independent.
Two balls are drawn at random with replacement from a box containing $10$ black and $8$ red balls. Find the probability that One of them is black and other is red.
One card is drawn at random from a well shuffled deck of $52$ cards. In which of the following cases are the events $\mathrm{E}$ and $\mathrm{F}$ independent ?
$E:$ 'the card drawn is a spade'
$F:$ 'the card drawn is an ace'
$A, B, C$ are any three events. If $P (S)$ denotes the probability of $S$ happening then $P\,(A \cap (B \cup C)) = $
A die is thrown. Let $A$ be the event that the number obtained is greater than $3.$ Let $B$ be the event that the number obtained is less than $5.$ Then $P\left( {A \cup B} \right)$ is
Probability that a student will succeed in $IIT$ entrance test is $0.2$ and that he will succeed in Roorkee entrance test is $0.5$. If the probability that he will be successful at both the places is $0.3$, then the probability that he does not succeed at both the places is