The probability that at least one of $A$ and $B$ occurs is $0.6$. If $A$ and $B$ occur simultaneously with probability $0.3$,then $P(A') + P(B') = $

If $\frac{1 - 3p}{2}, \frac{1 + 4p}{3}$ and $\frac{1 + p}{6}$ are the probabilities of three mutually exclusive and exhaustive events,then the set of all values of $p$ is

Two dice are rolled. If both dice have six faces numbered $1, 2, 3, 5, 7,$ and $11,$ then the probability that the sum of the numbers on the top faces is less than or equal to $8$ is

Three coins are tossed once. Let $A$ denote the event 'three heads show',$B$ denote the event 'two heads and one tail show',$C$ denote the event 'three tails show',and $D$ denote the event 'a head shows on the first coin'. Which events are simple?

The probability that a person $A$ completes a work in a given time is $\frac{2}{3}$ and the probability that another person $B$ completes the same work in the same time is $\frac{3}{4}$. If both $A$ and $B$ start doing this work at the same time,then the probability that the work is completed in the given time is

Three coins are tossed. Describe two events which are mutually exclusive but not exhaustive.