Answer:
1728
Explanation:
Strategic Advice: You can tell from the length of the question that you can simply skim the first couple of sentences. You also need to make sure you answer the right question (how many masks the hospital would receive if it ordered all of the boxes of 144 the supplier has in stock).
Getting to the Answer: Create a system of linear equations where x represents the number of boxes with 48 masks and y represents the number of boxes with 144 masks. The first equation should represent the total number of boxes, x + y = 35. The second equation should represent the total number of masks. Because x represents boxes with 48 masks and y represents boxes with 144 masks, the second equation is 48x + 144y = 2,832. Now solve the system using substitution.