Three unbiased coins are tossed. Then,the probability of getting at most two heads is

If $A$ and $B$ are two events with $P(A \cup B) = 0.65$ and $P(A \cap B) = 0.15$,then find the value of $P(A^C) + P(B^C)$.

$A$ man and his wife appear for an interview for two posts. The probability of the husband's selection is $\frac{1}{7}$ and that of the wife's selection is $\frac{1}{5}$. If they appear for the interview independently,then the probability that only one of them is selected is:

Let $A$ and $B$ be events for which $P(A) = x$,$P(B) = y$,and $P(A \cap B) = z$. Then $P(\bar{A} \cap B)$ equals:

$A$ student appears for tests $I$,$II$,and $III$. The student is successful if they pass in tests ($I$ and $II$) $OR$ ($I$ and $III$). The probabilities of the student passing in tests $I$,$II$,and $III$ are respectively $p$,$q$,and $1/2$. If the probability of the student being successful is $1/2$,then:

Four persons can hit a target correctly with probabilities $\frac{1}{2}, \frac{1}{3}, \frac{1}{4}$ and $\frac{1}{8}$ respectively. If all hit at the target independently,then the probability that the target would be hit is: