If $20$ markers are drawn from a large number of markers in which 10% of them are red markers. What is the probability that number of red markers drawn exceeds the expectation of number of red markers ? (Use poisson distribution).
Here mean or expectation is calculated as $20\cdot\frac{1}{10} = 2$.
Now
$$P(X > 2) = 1 - \Big( P(X=0) + P(X=1) + P(X=2)\Big) = 1 - 5e^{-2}\approx0.323$$
Here I don't understand how can we pick more than $2$ markers if only $10%$ of $20$ markers $2$ are red. I think it should be $0$ as we only have $2$ red markers and we can't pick more than $2$ red markers.