assume 10% of all plants in a field are infected. suppose you pick 20 plants at random from this field, which is so large that the percentage of infected plants does not change with the removal of the plants. what is the probability that at least one of them is infected?

Question

assume 10%  of all plants in a field are infected. suppose you pick 20 plants at random from this field, which is so large that the percentage of infected plants does not change with the removal of the plants. what is the probability that at least one of them is infected?

anonymous · Answer

at least one is a set up for not none
probability one is not infected is .9
probability 20 in a row are not infected is $.9^{20}$
probability that at least one is infected is $1-.9^{20}$

anonymous · Answer

then u add the probability of both infected and not infected?