Prove that if $E$ and $F$ are independent events, then so are the events $\mathrm{E}$ and $\mathrm{F}^{\prime}$.

Vedclass pdf generator app on play store
Vedclass iOS app on app store

since $\mathrm{E}$ and $\mathrm{F}$ are independent, we have

$\mathrm{P}(\mathrm{E} \cap \mathrm{F})=\mathrm{P}(\mathrm{E}) \cdot \mathrm{P}(\mathrm{F})$       ......... $(1)$

From the venn diagram in Fig it is clear that $E \cap \mathrm{F}$ and $\mathrm{E} \cap \mathrm{F}^{\prime}$ are mutually exclusive events and also $\mathrm{E}=(\mathrm{E} \cap \mathrm{F}) \cup\left(\mathrm{E} \cap \mathrm{F}^{\prime}\right)$

Therefore        $\quad P(E)=P(E \cap F)+P\left(E \cap F^{\prime}\right)$

or                   $P\left(E \cap F^{\prime}\right)=P(E)-P(E \cap F)$

                    $=\mathrm{P}(\mathrm{E})-\mathrm{P}(\mathrm{E}) \cdot \mathrm{P}(\mathrm{F})$    (by $(1))$

                   $=\mathrm{P}(\mathrm{E})(1-\mathrm{P}(\mathrm{F}))$

                   $=\mathrm{P}(\mathrm{E})$ . $\mathrm{P}\left(\mathrm{F}^{\prime}\right)$

Hence, $\mathrm{E}$ and $\mathrm{F}^{\prime}$ are independent

863-s41

Similar Questions

If $A$ and $B$ are any two events, then $P(\bar A \cap B) = $

A box of oranges is inspected by examining three randomly selected oranges drawn without replacement. If all the three oranges are good, the box is approved for sale, otherwise, it is rejected. Find the probability that a box containing $15$ oranges out of which $12$ are good and $3$ are bad ones will be approved for sale.

Fill in the blanks in following table :

$P(A)$ $P(B)$ $P(A \cap B)$ $P (A \cup B)$
$0.35$  ........... $0.25$  $0.6$

If $A$ and $B$ are any two events, then the probability that exactly one of them occur is

  • [IIT 1984]

A die is loaded in such a way that each odd number is twice as likely to occur as each even number. If $E$ is the event that a number greater than or equal to $4$ occurs on a single toss of the die then $P(E)$ is equal to