What is the probability of getting at least $1$ tail when a coin is tossed $4$ times?

$A$ box contains $100$ bulbs,out of which $10$ are defective. $A$ sample of $5$ bulbs is drawn. The probability that none is defective is

Find the binomial probability distribution whose mean is $3$ and variance is $2$.

During the winter months,in a certain village in Scotland,the probability of a day having severe fog is $0.6$. The probability that in a given week there will be exactly two days with severe fog is:

An urn contains $25$ balls,of which $10$ balls bear a mark $'X'$ and the remaining $15$ bear a mark $'Y'$. $A$ ball is drawn at random from the urn,its mark is noted down,and it is replaced. If $6$ balls are drawn in this way,find the probability that at least one ball will bear the $'Y'$ mark.

Let $X \sim B(n, p)$. If $E(X) = 2$ and $Var(X) = 1$, then the probability of getting at most one success is .....