Six boys and six girls sit in a row. What is the probability that the boys and girls sit alternatively?

If three dice are thrown simultaneously,then the probability of getting a score of $7$ is

$A$ box contains $12$ balls,of which $4$ are red,$5$ are green,and $3$ are white. If $3$ balls are drawn at random simultaneously from the box,then the probability that exactly $2$ balls have the same colour is

Four cards are drawn at random from a pack of $52$ playing cards. The probability of getting all four cards of the same suit is

Find the probability that when a hand of $7$ cards is drawn from a well-shuffled deck of $52$ cards,it contains exactly $3$ Kings.

The probability of forming a $12$-person committee from $4$ engineers,$2$ doctors,and $10$ professors containing at least $3$ engineers and at least $1$ doctor is: