Three coins are tossed once. Find the probability of getting $3$ heads.

What is the probability that a randomly selected leap year has $53$ Sundays or $53$ Mondays? Express your answer as the numerator of the fraction (in $/7$).

Two numbers $a$ and $b$ are chosen at random from the set of first $30$ natural numbers. Then the probability that $a^2 - b^2$ is divisible by $3$ is (in $/87$)

Two dice are thrown simultaneously. The probability of obtaining a total score of $5$ is

$A$ lot consists of $12$ good pencils,$6$ with minor defects,and $2$ with major defects. $A$ pencil is chosen at random. The probability that this pencil is not defective is

$A$ card is drawn at random from a well-shuffled pack of $52$ cards. The probability that it is a black card or a face card is