Since the package of 500 sheets has dimensions of
Since 7000 sheets will need to be put in
14 similar package
Since the dimensions of the case are
The length and the width of the package are the same as the length and the width of the case
Then we will use the heights of them to find how many package we can put in the case
That means we can fill the case with 6 packages
Since we have 14 packages, then we will need 6 + 6 + 2
3 cases 2 full and one has 2 packages only