$A$ card is drawn at random from a pack of $52$ cards. The probability of this card being a red card or a queen is:

Given $P(A) = \frac{3}{5}$ and $P(B) = \frac{1}{5}$. Find $P(A \text{ or } B)$,if $A$ and $B$ are mutually exclusive events.

$A$ coin is tossed twice. If events $A$ and $B$ are defined as: $A = \text{head on first toss}$,$B = \text{head on second toss}$. Then the probability of $A \cup B = $

$A$,$B$,and $C$ are three events,one of which must and only one can happen. The odds in favor of $A$ are $4 : 6$,and the odds against $B$ are $7 : 3$. Thus,the odds against $C$ are:

If the probability of an event occurring is $3:8$,what is the probability of the event not occurring?

If the odds against $A$ solving a problem are $4:3$ and the odds in favor of $B$ solving the problem are $7:5$,what is the probability that only one of them solves the problem?