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') = $

When three coins are tossed simultaneously,what is the probability of getting a head on the first,a tail on the second,and a head on the third?

One die of red colour,one of white colour and one of blue colour are placed in a bag. One die is selected at random and rolled,its colour and the number on its uppermost face is noted. Describe the sample space.

For two events $A$ and $B$,if $P(A \cup B) = \frac{3}{4}$,$P(A \cap B) = \frac{1}{4}$,and $P(A') = \frac{2}{3}$,then find $P(A' \cap B)$.

If $A$ and $B$ are events having probabilities $P(A)=0.6$, $P(B)=0.4$, and $P(A \cap B)=0$, then the probability that neither $A$ nor $B$ occurs is

The probability of getting head and tail alternately in three throws of a coin (or a throw of three coins) is: