$A$ coin is tossed $4$ times. The probability that at least one head turns up 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 successively three times. The probability of getting exactly one head or $2$ heads is:

The probability that an event $A$ happens in a trial is $0.4$. If three independent trials are made,then the probability that $A$ happens at least once is

Four fair dice are thrown independently $27$ times. Then the expected number of times,at least two dice show up a $3$ or a $5$ is

If $X \sim B(9, p)$ is a binomial variate satisfying the equation $P(X=3)=P(X=6)$,then $P(X < 3)=$