Suppose that a small hospital's emergency room has an average of 12 admissions per Saturday night. If you were a doctor working overtime on such a Saturday night, you might want to know the probability of having a quiet night, one that would let you catch on some much-needed sleep. Let's call a quiet night one in which two or fewer admissions take place. Assuming that the admissions follow a Poisson distribution, what is the probability that you get some sleep?

***Please have answers to 6 decimals or a fraction***