$A$ die is tossed $5$ times. Getting an odd number is considered a success. Then the variance of the distribution of success is

In a random experiment of throwing $5$ coins, the number of heads is defined as a random variable. The mean of the random variable is

Two cards are drawn at random one after the other with replacement from a pack of playing cards. If $X$ is the random variable denoting the number of ace cards drawn, then the mean of the probability distribution of $X$ is

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

Each of the persons $A$ and $B$ independently tosses three fair coins. The probability that both of them get the same number of heads is:

If $X$ has a binomial distribution,$B(n, p)$ with parameters $n$ and $p$ such that $P(X = 2) = P(X = 3)$,then $E(X)$,the mean of variable $X$,is