$A$ bag contains $4$ red and $3$ black balls. $A$ second bag contains $2$ red and $3$ black balls. One bag is selected at random. If from the selected bag,one ball is drawn at random,then the probability that the ball drawn is red,is

When a missile is fired from a ship,the probability that it is intercepted is $\frac{1}{3}$ and the probability that the missile hits the target,given that it is not intercepted,is $\frac{3}{4}$. If three missiles are fired independently from the ship,then the probability that all three hit the target is:

Two coins and one die are tossed. What is the probability of getting heads on both coins and $3$ or $6$ on the die?

Bag $B_1$ contains $4$ white and $2$ black balls. Bag $B_2$ contains $3$ white and $4$ black balls. $A$ bag is chosen at random and a ball is drawn from it at random,then the probability that the ball drawn is white,is

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 $X$ contains $2$ white and $3$ black balls and another bag $Y$ contains $4$ white and $2$ black balls. One bag is selected at random and a ball is drawn from it. Then,the probability for the ball chosen to be white is: