Final answer:
The delivery person can bring up a maximum of 12 boxes of books in the service elevator at one time, as the combined weight of the person and 12 boxes does not exceed the elevator's maximum capacity.
Step-by-step explanation:
The student's question pertains to how many boxes of books a delivery person can bring up in a service elevator without exceeding its maximum capacity. To solve this, we need to calculate the total weight that the elevator can hold, then subtract the weight of the delivery person to find the remaining capacity for the boxes of books.
Firstly, we note that the delivery person weighs 140 lbs, and each box of books weighs 50 lbs. The service elevator has a maximum capacity of 770 lbs. The remaining capacity for the boxes can be calculated as:
Remaining capacity = Maximum capacity - Person's weight = 770 lbs - 140 lbs = 630 lbs
Now, we divide the remaining capacity by the weight of a single box to determine the number of boxes:
Number of boxes = Remaining capacity / Weight per box = 630 lbs / 50 lbs = 12.6
Since we cannot have a fraction of a box, the delivery person can bring up 12 boxes of books in one trip with the service elevator.