A bag contains $5$ distinct Red, $4$ distinct Green and $3$ distinct Black balls. Balls are drawn one by one without replacement,then the probability of getting a particular red ball in fourth draw is-
$\frac{1}{12}$
$\frac{223}{1188}$
$\frac{335}{1320}$
$\frac{5}{12}$
Each of the persons $\mathrm{A}$ and $\mathrm{B}$ independently tosses three fair coins. The probability that both of them get the same number of heads is :
Six boys and six girls sit in a row. What is the probability that the boys and girls sit alternatively
Three squares of a chess board are chosen at random, the probability that two are of one colour and one of another is
From a pack of playing cards three cards are drawn simultaneously. The probability that these are one king, one queen and one jack is
A bag contains $3$ red, $4$ white and $5$ black balls. Three balls are drawn at random. The probability of being their different colours is