If in a lottery there are $5$ prizes and $20$ blanks,then the probability of getting a prize is

$A$ card is selected from a pack of $52$ cards. Calculate the probability that the card is an ace of spades.

The probability of happening an event $A$ is $0.5$ and that of $B$ is $0.3$. If $A$ and $B$ are mutually exclusive events,then the probability of happening neither $A$ nor $B$ is

The probabilities of three students solving a question are $\frac{1}{2}, \frac{1}{4},$ and $\frac{1}{6}$ respectively. What is the probability that the question is solved?

The probability of obtaining an even prime number on each die,when a pair of dice is rolled,is . . . . . . .

If $A$ and $B$ are two events of a random experiment such that $P(A \cup B) = P(A \cap B)$, then which one amongst the following four options is not true?