The probability that a randomly chosen $5-digit$ number is made from exactly two digits is

Two persons each make a single throw with a die. The probability they get equal value is $p_1$. Four persons each make a single throw and the probability of exactly three being equal is $p_2$,then:

If the papers of $4$ students can be checked by any one of $7$ teachers,then the probability that all the $4$ papers are checked by exactly $2$ teachers is (in $/49$)

An urn contains $8$ red and $5$ white balls. Three balls are drawn at random. Then, the probability that balls of both colours are drawn is

$A$ 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

$A$ bag contains $6$ white and $4$ black balls. Two balls are drawn at random. The probability that they are of the same colour is . . . . . .