Three numbers are selected randomly between $1$ to $20$. Then,the probability that they are consecutive numbers will be

$A$ bag contains $6$ red,$5$ white and $4$ black balls. Two balls are drawn. The probability that none of them is red,is

Two numbers $b$ and $c$ are chosen at random in succession without replacement from the set $\{1, 2, 3, \ldots, 9\}$. Then the probability that $x^2 + bx + c > 0, \forall x \in R$ is

If out of $20$ consecutive whole numbers two are chosen at random,then the probability that their sum is odd,is

From a class of $12$ girls and $18$ boys,two students are chosen randomly. What is the probability that both of them are girls?

Find the probability that a two-digit number formed by the digits $1, 2, 3, 4, 5$ is divisible by $4$ (repetition of digits is allowed).