Final answer:
The total weight of the four boxes is calculated by adding the individual weights together, resulting in a total weight of 75 pounds.
Step-by-step explanation:
To find the total weight of all the boxes, you simply add the weight of each box together:
10 pound box20 pound box40 pound box5 pound box
Now let's calculate the total:
10 pounds + 20 pounds + 40 pounds + 5 pounds = 75 pounds
The correct answer is C) 75 pounds.