Two cards are drawn successively with replacement from a well-shuffled pack of $52$ cards. The mean of the number of tens is:

In an examination,there are $10$ true-false type questions. Out of $10$,a student can guess the answer of $4$ questions correctly with probability $\frac{3}{4}$ and the remaining $6$ questions correctly with probability $\frac{1}{4}$. If the probability that the student guesses the answers of exactly $8$ questions correctly out of $10$ is $\frac{27 k}{4^{10}}$,then $k$ is equal to

In a Binomial distribution,$n=4$ and $2 P(X=3)=3 P(X=2)$,then $q=$

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

If the sum and the product of the mean and variance of a binomial distribution are $24$ and $128$ respectively,then the probability of one or two successes is:

From a lot containing $10$ defective and $90$ non-defective bulbs,$8$ bulbs are selected one by one with replacement. Then the probability of getting at least $7$ defective bulbs is: