The probability of any event cannot be ..........

When a balanced die is rolled,the probability of getting a multiple of $3$ on it is $\ldots \ldots \ldots .$

When we toss a coin,there are two possible outcomes - Head or Tail. Therefore,the probability of each outcome is $\frac{1}{2}$. Justify your answer.

$A$ balanced die is thrown once. Find the probability of getting a prime number.

$A$ card is drawn at random from a well-shuffled pack of $52$ cards. The probability of that card being a card of a black suit is .............

Total number of outcomes in the experiment of rolling two balanced dice once is ..........