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

If $X \sim B(4, p)$ and $2 P(X=3)=3 P(X=2)$,then the value of $p$ is:

If the mean and the variance of a binomial variate $X$ are $1$ and $0.75$ respectively, then which of the following is true?

In a random experiment,two dice are thrown and the sum of the numbers appeared on them is recorded. This experiment is repeated $9$ times. If the probability that a sum of $6$ appears at least once is $P_1$ and a sum of $8$ appears at least once is $P_2$,then $P_1 : P_2 =$

The items produced by a firm are supposed to contain $5\%$ defective items. The probability that a sample of $8$ items will contain less than $2$ defective items is:

In a binomial distribution,the probability of success is $\frac{1}{4}$ and the standard deviation is $3$. Then,its mean is