$A$ die is thrown. Find the probability of the following event: $A$ prime number will appear.

In a simultaneous throw of a pair of dice,the probability of getting a total more than $7$ is

$A$ man and his wife appear for an interview for two posts. The probability of the husband's selection is $\frac{1}{7}$ and that of the wife's selection is $\frac{1}{5}$. What is the probability that only one of them will be selected?

The probabilities of solving a specific problem independently by $A$ and $B$ are $\frac{1}{2}$ and $\frac{1}{3}$ respectively. If both try to solve the problem independently,find the probability that exactly one of them solves the problem.

$A$ coin is tossed again and again. If tail appears on the first three tosses,then the chance that head appears on the fourth toss is

If $x$ is chosen at random from the set $\{1, 2, 3, 4\}$ and $y$ is chosen at random from the set $\{5, 6, 7\}$,then the probability that $xy$ will be even is