Answer:
Step-by-step explanation:
From the given information:
A sandwich shop offers eight types of sandwiches, and Jamey likes all of them equally.
The probability that Jamey picks any one of them is 1/8
Suppose
X represents the number of times he chooses salami
Y represents the number of times he chooses falafel
Z represents the number of times he chooses veggie
Then X+Y+Z ≤ 5 and;
5-X-Y-Z represents the no. of time he chooses the remaining
8 - 3 = 5 sandwiches
However, the objective is to determine the P[X=x,Y=y,Z=z] such that 0≤x,y,z≤5
So, since he chooses x no. of salami sandwiches with probability (1/8)x
and y number of falafel with probability (1/8)y
and for z (1/8)z
Therefore, the remaining sandwiches are chosen with probability ![\dfrac{5}{8} (5-x-y-z)](https://tex.z-dn.net/?f=%5Cdfrac%7B5%7D%7B8%7D%20%285-x-y-z%29)
So. these x days, y days and z days can be arranged within five days in
![= \dfrac{5!}{x!y!z!(5-x-y-z)!}](https://tex.z-dn.net/?f=%3D%20%5Cdfrac%7B5%21%7D%7Bx%21y%21z%21%285-x-y-z%29%21%7D)
Thus;
![P[X=x,Y=y,Z=z]= \dfrac{5!}{x!y!z!(5-x-y-z)} \times \dfrac{1}{8}x*\dfrac{1}{8}y* \dfrac{1}{8}z* \dfrac{5}{8}(5-x-y-z)](https://tex.z-dn.net/?f=P%5BX%3Dx%2CY%3Dy%2CZ%3Dz%5D%3D%20%20%5Cdfrac%7B5%21%7D%7Bx%21y%21z%21%285-x-y-z%29%7D%20%20%5Ctimes%20%5Cdfrac%7B1%7D%7B8%7Dx%2A%5Cdfrac%7B1%7D%7B8%7Dy%2A%20%5Cdfrac%7B1%7D%7B8%7Dz%2A%20%5Cdfrac%7B5%7D%7B8%7D%285-x-y-z%29)
since 0 ≤ x, y, z ≤ 5 and x + y + z ≤ 5.
The distribution is said to be Multinomial distribution.