$A$ person can kill a bird with a probability of $3/4$. He tries $5$ times. What is the probability that he may not kill the bird at all?

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

Numbers are selected at random,one at a time from the two-digit numbers $00, 01, 02, \dots, 99$ with replacement. An event $E$ occurs only if the product of the two digits of a selected number is $24$. If four numbers are selected,then the probability that the event $E$ occurs at least $3$ times is:

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

$A$ fair coin is tossed $100$ times. The probability of getting tails an odd number of times 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