When a pair of six-faced fair dice are thrown, the probability that the sum of the numbers on the two dice is greater than $7$ is:

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

Three persons $P, Q$ and $R$ independently try to hit a target. If the probabilities of their hitting the target are $\frac{3}{4}, \frac{1}{2}$ and $\frac{5}{8}$ respectively,then the probability that the target is hit by $P$ or $Q$ but not by $R$ is

$A$ bag contains $3$ white,$3$ black and $2$ red balls. Three balls are drawn one by one without replacement. The probability that the third ball is red is:

The chances to fail in Physics are $20 \%$ and the chances to fail in Mathematics are $10 \%$. What are the chances to fail in at least one subject (in $\%$)?

If two events $A$ and $B$ are such that $P(A \cup B) = \frac{5}{6}$,$P(A \cap B) = \frac{1}{3}$,and $P(\bar{A}) = \frac{1}{2}$,then the events $A$ and $B$ are: