When success is not an impossible event,then the mean of Binomial distribution is

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

The probability that a person is not a sportsperson is $\frac{1}{6}$. Then the probability that out of the $6$ members of the family,$5$ are sportspersons is

For $X \sim B(n, p)$,if $p=0.6$ and $E(X)=6$,then $\operatorname{Var}(X)=$

Let $X \sim B(n, p)$. If $E(X)=5$ and $\operatorname{Var}(X)=2.5$,then find $P(X < 1)$.

$A$ lot of $100$ bulbs contains $10$ defective bulbs. Five bulbs are selected at random from the lot and are sent to a retail store. Then the probability that the store will receive at most one defective bulb is