The variance of binomial distribution with variables $n=5, p=0.30$ is . . . . . . .

If $x$ denotes the number of sixes in four consecutive throws of a dice,then $P(x = 4)$ is

At least how many times must a fair coin be tossed so that the probability of getting at least one head is at least $0.8$?

The probability that a student is not a swimmer is $\frac{1}{5}$. Then the probability that out of five students,four are swimmers is

If $X \sim B(6, p)$ is a binomial variate and $\frac{P(X=4)}{P(X=2)}=\frac{1}{9}$,then $p=$

$A$ fair coin is tossed a fixed number of times. If the probability of getting five heads is equal to that of getting seven heads,then the probability of getting four heads is