If three dice are thrown together,then the probability of getting $5$ on at least one of them is

In a tournament,a team plays $10$ matches with probabilities of winning and losing each match as $\frac{1}{3}$ and $\frac{2}{3}$ respectively. Let $x$ be the number of matches that the team wins,and $y$ be the number of matches that the team loses. If the probability $P(|x-y| \leq 2)$ is $p$,then $3^9 p$ equals....................

If $X$ is a binomial variate with the range $\{0, 1, 2, 3, 4, 5, 6\}$ and $P(X=2) = 4 P(X=4)$,then the parameter $p$ of $X$ is

$A$ discrete random variable $X$ has the distribution $B(15, p)$. Given that $\operatorname{Var}(X) = 3.15$. Then,the two possible values of $p$ are

For an entry to a certain course,a candidate is given $20$ problems to solve. If the probability that the candidate can solve any problem is $\frac{3}{7}$,then the probability that he is unable to solve at most $2$ problems is

$A$ multiple choice examination has $5$ questions. Each question has three alternative answers of which exactly one is correct. The probability that a student will get $4$ or more correct answers just by guessing is