Answer:
The weight of each box is 0.4 pounds.
Step-by-step explanation:
Given:
Ben orders a case of his favorite macaroni and cheese.
The case contains 18 same size boxes that weigh a total of 7.2 pounds.
Now, to find the weight of each box of macaroni and cheese.
Let the weight of each box be 
Number of boxes in a case = 18.
The total weight = 7.2 pounds.
According to question:


<em>Dividing both sides by 18 we get:</em>

Therefore, the weight of each box is 0.4 pounds.