I think it's 462.99, rounded it's 463
Let X be the number of lightning strikes in a year at the top of particular mountain.
X follows Poisson distribution with mean μ = 3.8
We have to find here the probability that in randomly selected year the number of lightning strikes is 0
The Poisson probability is given by,
P(X=k) = 
Here we have X=0, mean =3.8
Hence probability that X=0 is given by
P(X=0) = 
P(X=0) = 
P(X=0) = 0.0224
The probability that in a randomly selected year, the number of lightning strikes is 0 is 0.0224
353/12 =29.41. But will have to round up to 30 so the answer is 30
1/2 ( -3/2 + 6x + 1) - 3x
Simplify:
= 1/2 (-1/2 + 6x) - 3x
Apply distributive property:
= -1/4 + 3x -3 x
Simplify:
= -1/4