Gopi buys a fish from a shop for his aquarium. The shopkeeper takes out one fish at random from a tank containing $5$ male fish and $8$ female fish. What is the probability that the fish taken out is a male fish?

There are $40$ students in Class $X$ of a school,of whom $25$ are girls and $15$ are boys. The class teacher has to select one student as a class representative. She writes the name of each student on a separate card,the cards being identical. Then she puts cards in a bag and stirs them thoroughly. She then draws one card from the bag. What is the probability that the name written on the card is the name of $(i)$ a girl? $(ii)$ a boy?

One card is drawn from a well-shuffled deck of $52$ cards. Calculate the probability that the card will
$(i)$ be an ace,
$(ii)$ not be an ace.

$A$ jar contains $24$ marbles,some are green and others are blue. If a marble is drawn at random from the jar,the probability that it is green is $\frac{2}{3}$. Find the number of blue balls in the jar.

$A$ box contains $12$ balls out of which $x$ are black. If one ball is drawn at random from the box,what is the probability that it will be a black ball?
If $6$ more black balls are put in the box,the probability of drawing a black ball is now double of what it was before. Find $x$.

$A$ child has a die whose six faces show the letters as given below:
$A$,$B$,$C$,$D$,$E$,$A$
The die is thrown once. What is the probability of getting:
$(i)$ $A$?
(ii) $D$?