Answer:
(a) The probability of more than one death in a corps in a year is 0.1252.
(b) The probability of no deaths in a corps over 7 years is 0.0130.
Step-by-step explanation:
Let <em>X</em> = number of soldiers killed by horse kicks in 1 year.
The random variable
.
The probability function of a Poisson distribution is:

(a)
Compute the probability of more than one death in a corps in a year as follows:
P (X > 1) = 1 - P (X ≤ 1)
= 1 - P (X = 0) - P (X = 1)

Thus, the probability of more than one death in a corps in a year is 0.1252.
(b)
The average deaths over 7 year period is: 
Compute the probability of no deaths in a corps over 7 years as follows:

Thus, the probability of no deaths in a corps over 7 years is 0.0130.
1. It's a proportion...50 over 12.5 = h over 50 then cross multiply and divide
2. Another proportion 7over x = 2 over 6 then cross multiply and divide
The answer is 5 cause two less then 7 is 5.
1/3 x 14
2/3 x 7
4/6 x 7
2/6 x 14
1/3 x 28/2
1/3 x 42/3
Moving left subtracts from the x value the number you move.
In (2,9) the x value is the number 2
You move 1 unit to the left so subtract 1 from 2:
2-1 = 1
You will be at (1,9)