Answer:
3,984.375 tons
Explanation:
First, let's convert the weight of one box from ounces to tons:
0.51 oz = 0.51/16 = 0.031875 lbs
1 lb = 0.0005 tons (since 1 ton = 2000 lbs)
0.031875 lbs = 0.031875 x 0.0005 = 0.0000159375 tons
Next, let's calculate the total weight of cardboard needed for 250 million boxes:
Total weight of cardboard = weight of one box x number of boxes
Total weight of cardboard = 0.0000159375 tons x 250,000,000
Total weight of cardboard = 3,984.375 tons