$A$ bag contains $3$ red,$5$ black and $7$ blue balls. If three balls are drawn at random simultaneously from the bag,then the probability of getting at least two blue balls is

If three smallest squares are chosen at random on a chess board,then the probability of getting them in such a way that they are all together in a row or in a column is

If $4$-digit numbers greater than $5,000$ are randomly formed from the digits $0, 1, 3, 5,$ and $7$,what is the probability of forming a number divisible by $5$ when the digits are repeated?

If $6$ girls and $5$ boys are sitting in a row,what is the probability that no two boys sit together?

If three integers are selected at random from the first $20$ integers,what is the probability that their product is even?

Two different families $A$ and $B$ are blessed with an equal number of children. There are $3$ tickets to be distributed amongst the children of these families so that no child gets more than one ticket. If the probability that all the tickets go to the children of family $B$ is $\frac{1}{12}$,then the number of children in each family is?