Gary takes a suitcase and a backpack on an airplane. The suitcase weighs 4 times as much as the backpack. The suitcase and the backpack together weigh 40 Ib.

I believe your answer would be that the backpack weighs 5 pounds.

Step-by-step explanation:

If the suitcase weighs 4 times as the backpack, that would be 8 pounds for the suitcase. Obviously we know a suitcase will weigh more than a backpack, so of course it weighs more. If you were to take a calculator and divide one digit numbers, the only non-(Ex. 16.66676493763) numbers would be 5 and 8. Therefore, since we know the suitcase weighs more than the backpack, 5 times 8 equals 40.

Hope this helps!!!