If $P(C) = \frac{2}{5}$,then $P(\bar{C}) = \ldots \ldots \ldots$

$A$ triangular target with sides measuring $5 \, cm, 12 \, cm$,and $13 \, cm$ is drawn on a square board with side $20 \, cm$. Find the probability that a dart hitting the board hits the target.

$A$ 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.

$A$ balanced die is thrown once. Find the probability of getting a number smaller than $4$.

There are chits numbered $1$ to $20$ in a box. One chit is drawn at random. Find the probability that the number on the chit is a prime number.

An unbiased coin is tossed thrice. The probability of receiving two heads is ..........