If $4$ boys and $3$ girls are standing in a row for an interview,what is the probability that they stand in alternating positions?

$A$ five-digit number is formed by the digits $1, 2, 3, 4, 5$ with no digit being repeated. The probability that the number is divisible by $4$ is

$A$ flashlight has $10$ batteries,out of which $4$ are dead. If $3$ batteries are selected without replacement and tested,then the probability that all $3$ are dead is:

If the letters of the word $ASSASSIN$ are arranged in a row at random,what is the probability that no two $S$s occur together?

Out of $30$ consecutive numbers,$2$ are chosen at random. The probability that their sum is odd,is

An urn contains $6$ yellow balls and $x$ black balls. When two balls are drawn at random,the probability that both are yellow is $\frac{5}{26}$,then the value of $x$ is