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

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

On her vacations,Veena visits four cities ($A, B, C$,and $D$) in a random order. What is the probability that she visits $A$ before $B$ and $B$ before $C$?

$A$ bag contains $5$ white,$7$ black,and $4$ red balls. If three balls are drawn at random from the bag,what is the probability that all three balls are white?

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

Two cards are drawn at random from a pack of $52$ cards. The probability that both are the cards of spade is