In a simultaneous throw of three coins,what is the probability of getting at least $2$ tails?

$A$ set $S$ contains $7$ elements. $A$ non-empty subset $A$ of $S$ and an element $x$ of $S$ are chosen at random. Then the probability that $x \in A$ is

$A$ die is thrown. Find the probability of the following event: $A$ number greater than or equal to $3$ will appear.

$A, B, C$ are any three events. If $P(S)$ denotes the probability of $S$ happening,then $P(A \cap (B \cup C)) = $

$A$ problem in mathematics is given to $4$ students whose chances of solving it individually are $\frac{1}{2}, \frac{1}{3}, \frac{1}{4},$ and $\frac{1}{5}.$ The probability that the problem will be solved by at least one student is

Three coins are tossed once. Find the probability of getting at least $2$ heads.