$A$ bag contains $3$ red,$7$ white and $4$ black balls. If three balls are drawn from the bag,then the probability that all of them are of the same colour is

Let $\omega$ be a complex cube root of unity with $\omega \neq 1$. $A$ fair die is thrown three times. If $r_1, r_2,$ and $r_3$ are the numbers obtained on the die,what is the probability that $\omega^{r_1} + \omega^{r_2} + \omega^{r_3} = 0$?

$A$ die marked with digits $\{1, 2, 2, 3, 3, 3\}$ is thrown three times. The probability of getting a sum of $6$ on the faces of the die is equal to:

If the letters of the word $SUCCESS$ are rearranged,what is the probability that all identical letters come together (in $/35$)?

$A$ bag contains $6$ red,$4$ white,and $8$ blue balls. If three balls are drawn at random,then the probability that $2$ are white and $1$ is red is:

Two numbers $a$ and $b$ are chosen at random from the set of the first $30$ natural numbers. The probability that $a^2 - b^2$ is divisible by $3$ is