If $P(A) : P(\bar{A}) = 5 : 3$,then $P(\bar{A}) = $ ........

$A$ student says that if you throw a die,it will show up $1$ or not $1$. Therefore,the probability of getting $1$ and the probability of getting 'not $1$' each is equal to $\frac{1}{2}$. Is this correct? Give reasons.

$A$ die is thrown twice. What is the probability that
$(i)$ $5$ will not come up either time?
$(ii)$ $5$ will come up at least once?

If the probability of an event is $p$,the probability of its complementary event will be

$A$ game consists of tossing a one rupee coin $3$ times and noting its outcome each time. Hanif wins if all the tosses give the same result,i.e.,three heads or three tails,and loses otherwise. Calculate the probability that Hanif will lose the game.

If $P(A) : P(\bar{A}) = 3 : 4$,then $P(A) =$ .........