A delivery person uses a service elevator to bring boxes of books up to an office. The delivery person weighs 160 lb and each box of books weighs 40 lb. The maximum capacity of the elevator is 1030 lb. How many boxes of books can the delivery person bring up at one​ time?

The delivery person can bring up ? boxes of books.

1 answer

The weight of the delivery person is 160 lb and each box of books weighs 40 lb. Let's assume the number of boxes of books that the delivery person can bring up at one time be x. Therefore, the total weight of the boxes with books that the delivery person can bring up is 40x lb.

According to the problem, the maximum capacity of the elevator is 1030 lb. So, we can write the equation:

40x + 160 ≤ 1030

Now, we solve this inequality to find the maximum number of boxes that can be brought up at one time.

Subtracting 160 from both sides:

40x ≤ 1030 - 160
40x ≤ 870

Dividing both sides by 40:

x ≤ 870/40
x ≤ 21.75

However, the number of boxes must be a whole number, so the delivery person can bring up a maximum of 21 boxes of books at one time.