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

Describe the sample space for the indicated experiment: $A$ coin is tossed three times.

From a pack of $52$ cards,one card is drawn at random. The probability that it is either a king or a queen is:

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 $/87$)

The probability of hitting a target by three marksmen are $\frac{1}{2}, \frac{1}{3}$ and $\frac{1}{4}$ respectively. The probability that one and only one of them will hit the target when they fire simultaneously,is

The probability that a randomly selected $2$-digit number belongs to the set $\{n \in N : (2^{n}-2) \text{ is a multiple of } 3\}$ is equal to: