The answer you are looking for is 2!!
It is 7-7-77-8-7-7-7777-75a
Answer:


Step-by-step explanation:
Given
See attachment for complete question
Solving (a): The entry C22
First, matrix C represents the inventory at the end of July.
The entry of C is calculated as:

i.e.
![C = \left[\begin{array}{ccc}543&356&643\\364&476&419\\376&903&409\end{array}\right] - \left[\begin{array}{ccc}102&78&97\\98&87&59\\54&89&79\end{array}\right]](https://tex.z-dn.net/?f=C%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D543%26356%26643%5C%5C364%26476%26419%5C%5C376%26903%26409%5Cend%7Barray%7D%5Cright%5D%20%20-%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D102%2678%2697%5C%5C98%2687%2659%5C%5C54%2689%2679%5Cend%7Barray%7D%5Cright%5D)
![C = \left[\begin{array}{ccc}543-102&356-78&643-97\\364-98&476-87&419-59\\376-54&903-89&409-79\end{array}\right]](https://tex.z-dn.net/?f=C%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D543-102%26356-78%26643-97%5C%5C364-98%26476-87%26419-59%5C%5C376-54%26903-89%26409-79%5Cend%7Barray%7D%5Cright%5D)
![C = \left[\begin{array}{ccc}441&278&546\\266&389&360\\322&814&330\end{array}\right]](https://tex.z-dn.net/?f=C%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D441%26278%26546%5C%5C266%26389%26360%5C%5C322%26814%26330%5Cend%7Barray%7D%5Cright%5D)
Item C22 means the entry at the second row and the second column.
From the matrix

Solving (b): The maximum A31 possible.
From the given data, we have:
![Inventory = \left[\begin{array}{ccc}543&356&643\\364&476&419\\376&903&409\end{array}\right]](https://tex.z-dn.net/?f=Inventory%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D543%26356%26643%5C%5C364%26476%26419%5C%5C376%26903%26409%5Cend%7Barray%7D%5Cright%5D)
![Unit\ Sales = \left[\begin{array}{ccc}102&78&97\\98&87&59\\54&89&79\end{array}\right]](https://tex.z-dn.net/?f=Unit%5C%20Sales%20%3D%20%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D102%2678%2697%5C%5C98%2687%2659%5C%5C54%2689%2679%5Cend%7Barray%7D%5Cright%5D)
From the matrices above.
A31 means entry at the 3rd row and 1st column.
So, the possible values of A31 are:

and

By comparison, 376 > 54
So: