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

In a Binomial distribution $B(n, p)$,the sum and product of the mean and the variance are $5$ and $6$ respectively,then $6(n+p-q)=$

$A$ coin is tossed $4$ times. The probability that at least one head turns up is

The maximum value of the variance of a Binomial distribution with parameters $n$ and $p$ is

One hundred identical coins,each with probability $p$ of showing up heads,are tossed once. If $0 < p < 1$ and the probability of heads showing on $50$ coins is equal to that of heads showing on $51$ coins,then the value of $p$ is

$A$ coin is tossed $10$ times. The probability of getting exactly six heads is