The probability that a bomb will miss the target is $0.2$. Then the probability that out of $10$ bombs dropped,exactly $2$ will hit the target is:

$A$ box contains $30$ toys of the same size,in which $10$ toys are white and the remaining toys are blue. $A$ toy is drawn at random from the box and it is replaced in the box after noting down its colour. If $5$ toys are drawn in this way,then the probability of getting at most $2$ white toys is

$A$ variable $X$ takes values $0, 0, 2, 6, 12, 20, ..., n(n-1)$ with frequencies $^nC_0, ^nC_1, ^nC_2, ^nC_3, ^nC_4, ^nC_5, ..., ^nC_n$, respectively. If the mean of this data is $60$, then its median is:

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

There are $6$ boxes labelled $B_1, B_2, \ldots, B_6$. In each trial,two fair dice $D_1, D_2$ are thrown. If $D_1$ shows $j$ and $D_2$ shows $k$,then $j$ balls are put into the box $B_k$. After $n$ trials,what is the probability that $B_1$ contains at most one ball?

$A$ fair coin is tossed $15$ times. The probability that the tail will appear at least thrice is