Answer
a)$4.32\times 10^{-5} $
b)$0.1257$
c)$0.9899$
Work Step by Step
Let $X$ be the random variable of number of visitors. $X$ has the binomial distribution with parameters $n=1000, p=0.01$,
The probability mass function of $X$ is given by:
$$
\mathbb{P}(X=x)=\left(\begin{array}{l}
1000 \\
x
\end{array}\right) 0.01^{x} \times(0.99)^{1000-x}, x=0,1, \ldots, 1000
$$
Calculate using this formula:
$$
\begin{array}{l}
\mathbb{P}(X=0)=4.32\times 10^{-5} \\
\mathbb{P}(X= 10)=0.1257\\
\mathbb{P}(X \gt 3)=1-(\mathbb{P}(X=0)+\mathbb{P}(X=1)+\mathbb{P}(X=2)+\mathbb{P}(X=3))=0.9899\\
\end{array}
$$
