For an event,the odds against are $6 : 5$. The probability that the event does not occur is

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

The probabilities that $A$ and $B$ speak the truth are $\frac{4}{5}$ and $\frac{3}{4}$ respectively. The probability that they contradict each other when asked to speak on a fact is

For two events $A$ and $B$,the probability that at least one of them occurs is $0.6$ and the probability that both occur is $0.2$. Then $P(A) + P(B) = \dots$

One card is drawn randomly from a pack of $52$ cards. The probability that it is a king or a spade is:

If the probability for $A$ to fail in an exam is $0.2$ and that for $B$ is $0.3$,then the probability that either $A$ or $B$ fails is $\leq \ldots \ldots$.