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

In a simultaneous throw of three coins,what is the probability of getting at least $2$ tails?

The probability that a student will pass the final examination in both English and Hindi is $0.5$ and the probability of passing neither is $0.1$. If the probability of passing the English examination is $0.75$,what is the probability of passing the Hindi examination?

Two dice are thrown. The events $A, B$ and $C$ are as follows:
$A:$ getting an even number on the first die.
$B:$ getting an odd number on the first die.
$C:$ getting the sum of the numbers on the dice $\leq 5$.
Describe the events $A$ and $B$.

An integer $x$ is chosen at random from $1$ to $50$. The probability that $x + \frac{336}{x} \leq 50$ is

$A$ bag contains $7$ green and $5$ black balls. $3$ balls are drawn at random one after the other. If the balls are not replaced,then the probability of all three balls being green is