The probability of a person hitting a bird is $3/4$. If he tries $5$ times,what is the probability that he will not hit the bird even once (in $/1024$)?

The probability that a person who undergoes a bypass surgery will recover is $0.6$. The probability that of the $6$ patients who undergo similar operations,half of them will recover is:

$A$ random variable $X$ follows the binomial distribution and $X \sim B(n, 0.3)$. If the mean of $X$ is three times as large as the standard deviation of $X$,then $n=$

An unbiased coin is tossed to get $2$ points for turning up a head and $1$ point for the tail. If three unbiased coins are tossed simultaneously, then the probability of getting a total of an odd number of points is

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

Two dice are thrown simultaneously. If $X$ denotes the number of sixes,then the expectation of $X$ is