The probability that 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.......

Let $X$ have a binomial distribution $B(n, p)$ such that the sum and the product of the mean and variance of $X$ are $24$ and $128$ respectively. If $P(X > n - 3) = \frac{k}{2^n}$,then $k$ is equal to.

$A$ shooter can hit a given target with probability $\frac{1}{4}$. She keeps firing a bullet at the target until she hits it successfully three times and then she stops firing. The probability that she fires exactly six bullets lies in the interval

$A$ coin is tossed $10$ times. The probability of getting exactly six heads is

How many times must a fair coin be tossed so that the probability of getting at least one head is at least $0.8$?

Two dice are thrown $4$ times simultaneously. What is the probability that both dice show the same numbers exactly twice?