$A$ die is thrown $5$ times. Getting an odd number is considered a success. Find the variance of the distribution of successes.

Ten bulbs are drawn successively,with replacement,from a lot containing $10 \%$ defective bulbs. The probability that there is at least one defective bulb is:

Let a random variable $X$ have a Binomial distribution with mean $8$ and variance $4$. If $P(X \leqslant 2) = \frac{k}{2^{16}}$,then $k$ is equal to:

Assuming that for a husband-wife couple,the chances of their child being a boy or a girl are the same,the probability of their two children being a boy and a girl is:

$A$ bag contains $30$ white balls and $10$ red balls. $16$ balls are drawn one by one randomly from the bag with replacement. If $X$ is the number of white balls drawn,then $\left( \frac{\text{mean of } X}{\text{standard deviation of } X} \right)$ is equal to

Find the mean of the Binomial distribution $B\left(4, \frac{1}{3}\right)$.