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'
In a deck of $52$ cards, $13$ cards are spades and $4$ cards are aces.
$\therefore $ $ \mathrm{P}(\mathrm{E})=\mathrm{P}$ (the card drawn is a spade) $=\frac{13}{52}=\frac{1}{4}$
$\therefore $ $ \mathrm{P}(\mathrm{F})=\mathrm{P}$ (the card drawn is a ace) $=\frac{4}{52}=\frac{1}{13}$
In the deck of cards, only $1$ card is an ace of spades.
$ \mathrm{P}(\mathrm{EF})=\mathrm{P}$ (the card drawn is spade and an ace) $=\frac {1}{52}$
$\mathrm{P}(\mathrm{E}) \times \mathrm{P}(\mathrm{F})=\frac{1}{4} \frac{1}{13}=\frac{1}{52}=\mathrm{P}(\mathrm{EF})$
$\Rightarrow \mathrm{P}(\mathrm{E}) \times \mathrm{P}(\mathrm{F})=\mathrm{P}(\mathrm{EF})$
Therefore, the events $\mathrm{E}$ and $\mathrm{F}$ are independent.
If $A$ and $B$ are any two events, then $P(A \cup B) = $
In a hostel, $60 \%$ of the students read Hindi newspaper, $40 \%$ read English newspaper and $20 \%$ read both Hindi and English newspapers. A student is selected at random. If she reads Hindi newspaper, find the probability that she reads English newspaper.
In a hostel, $60 \%$ of the students read Hindi newspaper, $40 \%$ read English newspaper and $20 \%$ read both Hindi and English newspapers. A student is selected at random. If she reads English newspaper, find the probability that she reads Hindi newspaper.
Suppose that $A, B, C$ are events such that $P\,(A) = P\,(B) = P\,(C) = \frac{1}{4},\,P\,(AB) = P\,(CB) = 0,\,P\,(AC) = \frac{1}{8},$ then $P\,(A + B) = $
If $P\,(A) = 0.4,\,\,P\,(B) = x,\,\,P\,(A \cup B) = 0.7$ and the events $A$ and $B$ are independent, then $x =$