The answer doesnt accept results using scipy, here's my code:

import math

res = (2.5**5)*math.exp(-2.5)/math.factorial(5)
print(res)

Python scipy made it easy:

from scipy.stats import poisson
poisson.pmf(k=5, mu=2.5)
0.0668

Straight forward application of the Poisson Distribution formula

0.0668

P(x=5) should be zero (or infinitely small). Also, we are not given upper or lower bounds for this distribution (i.e. what is the standard deviation?)

Shouldn't we need to subtract the upper-tail probability X>=6?