For $X \sim B(n, p)$,if $p=0.6$ and $E(X)=6$,then $\operatorname{Var}(X)=$

If a die is thrown $7$ times,what is the probability of getting exactly $5$ four times?

Ten bulbs are drawn successively,with replacement,from a lot containing $10 \%$ defective bulbs. The probability that there is at least one defective bulb is:

Among every $8$ units of a product, one is likely to be defective. If a consumer has ordered $5$ units of that product, then the probability that at most one unit is defective among them is

If the mean and the variance of a Binomial variate $X$ are $2$ and $1$ respectively,then the probability that $X$ takes a value greater than or equal to $1$ is

$A$ dice is thrown $(2n + 1)$ times. The probability of getting $1, 3$ or $4$ at most $n$ times is: