If $X \sim B(n, p)$ with $n = 10, p = 0.4$,then $E(X^2) =$

In a shelf, there are $3$ mathematics and $2$ physics books. $A$ student takes a book randomly. If he takes a book randomly, successively for $3$ times by replacing the book already taken every time, then the mean of the number of mathematics books, which is treated as a random variable, is:

If the mean and variance of a binomial variable $X$ are $2$ and $1$ respectively, then $P(X \geq 1)$ is equal to

The probability that $A$ wakes up before the alarm rings is $0.4$. Then,the mean and variance of the number of times $A$ wakes up before the alarm rings,in the next $7$ days respectively are:

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

Two cards are drawn successively with replacement from a well-shuffled pack of $52$ cards. Let $X$ denote the random variable of the number of jacks obtained in the two drawn cards. Then $P(X=1) + P(X=2)$ equals