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

Two cards are drawn without replacement from a well-shuffled pack. Find the probability that one of them is an ace of hearts.

$A$ bag contains $3$ red and $3$ white balls. If two balls are drawn one after another,what is the probability that they are of different colors?

If five-digit numbers are formed from the digits $0, 1, 2, 3, 4$ using every digit exactly once,then the probability that a randomly chosen number from those numbers is divisible by $4$ is:

Five persons enter a lift cabin in the cellar of a $7$-floor building (excluding the cellar). If each of them independently and with equal probability can leave the cabin at any floor out of the $7$ floors (beginning with the first), then the probability that all $5$ persons leave the cabin at different floors is:

$A$ bag contains $6$ white,$7$ red,and $5$ black balls. If $3$ balls are drawn from the bag at random,then the probability that all of them are white is