A, B and C are mutually exclusive and exhaustive events of a random experiment and $E$ is an event that occurs in conjunction with one of the events $\mathrm{A}, \mathrm{B}$ and $C$. The conditional probabilities of $E$ given the happening of $A, \mathrm{~B}$ and C are respectively $0.6,0.3$ and 0.1. If $P(A)=0.30$ and $P(B)=0.50$, then $P(C / E)=$

For the probability distribution of a discrete random variable $X$ as given below, then mean of $X$ is

X = x	-2	-1	0	1	2	3
P(X = x)	$$ \frac{1}{10} $$	$$ K+\frac{2}{10} $$	$$ K+\frac{3}{10} $$	$$ K+\frac{3}{10} $$	$$ K+\frac{4}{10} $$	$$ K+\frac{2}{10} $$

In a random experiment, two dice are thrown and the sum of the numbers appeared on them is recorded. This experiment is repeated 9 times. If the probability that a sum of 6 appears atleast once is $P_1$ and a sum of 8 appears atleast once is $P_2$, then $P_1: P_2=$

If 7 different balls are distributed among 4 different boxes, then the probability that the first box contains 3 balls is