solution:
Lets start with the most amount that could have been sold.......using guess and check, we can figure out that 290 salads could have been sold, while 8 cartons of milk would have been sold.
The least amount of salads that could have been sold were none.
so,
you have 0<s<290
at least none were sold, and at most 290 were sold
but I do believe you are missing part of the question
