If $A$ and $B$ are independent events and $P(A) = 0.4$,$P(A \cup B) = 0.6$,and $P(B) = p$,then the value of $p$ is . . . . . . .

$A$ and $B$ are independent events. Their probabilities are $3/10$ and $2/5$ respectively. What is the probability that exactly one of the events occurs?

If $A_i$ $(i=1, 2, 3, \ldots, n)$ are $n$ independent events with $P(A_i) = \frac{1}{1+i}$ for each $i$,then the probability that none of $A_i$ occurs is

$A$ bag contains $3$ white and $2$ black balls and another bag contains $2$ white and $4$ black balls. $A$ bag is chosen at random and a ball is picked up from it. The probability of the ball being black is:

$A$ bag contains $10$ similar balls,of which $4$ are blue and $6$ are red. Three balls are taken out at random from the bag one after the other without replacement. The probability that all the three balls drawn are red is

$A$ purse contains $4$ copper and $3$ silver coins. $A$ second purse contains $6$ copper and $2$ silver coins. If a coin is drawn from any one of these two purses,what is the probability that it is a copper coin?