Question 983441
I am assuming a Poisson function with lambda=3.  The number is small, it could be infinite, and they occur sporadically, so the assumption of a Poisson is reasonable.
The multiple choice makes this easier:
I can do the probability of 0,1,2,3 and subtract it from 1.  Everything else would be 4 or greater.
BUT, let me do just 4 and 5
exp(-3)3^x/x!

For x=4, that works out to 0.168
for x=5, that is e^-5(3^5/5!=0.014
x=6 will be still smaller, etc., because the further from the average, the smaller the value.
So, without computing the exact probability, I have found 0.182 is very close to the real probability and a little under.  Therefore, 0.185 is the answer.  A calculator would make this easier if one were so inclined.