There are $5$ white,$7$ red,$4$ black,and $2$ blue identical balls in a box. One ball is selected at random from the box. Find the probability that the selected ball is either white or blue.

$A$ card is drawn at random from a well-shuffled pack of $52$ cards. The probability of that card being a picture card is ...........

An unbiased coin is tossed thrice. Find the probability of the following event:
$C:$ at most $2$ heads are received. (in $/8$)

$A$ carton of $24$ bulbs contains $6$ defective bulbs. One bulb is drawn at random. What is the probability that the bulb is not defective? If the bulb selected is defective and it is not replaced, and a second bulb is selected at random from the rest, what is the probability that the second bulb is defective?

$A$ card is selected at random from a well-shuffled pack of $52$ cards. Find the probability that the selected card is the queen of hearts.

There are $5$ white,$7$ red,$4$ black and $2$ blue identical balls in a box. One ball is selected at random from the box. Find the probability that the selected ball is either red or black. (in $/18$)