17. A warehouse has 5 shelves long enough to hold 8 boxes and high enough to hold 4 boxes. All the shelves are full. How many boxes are there?

Total 20 boxes are there.

Step-by-step explanation:

Total number of shelves in a warehouse = 5 shelves.

Each shelve either can hold maximum 8 boxes with their lengths or can hold 4 boxes with their heights.

So, in that case only 4 boxes could be hold in each of 5 shelves because only 4 boxes could be fit with their heights.

Therefore, total number of boxes = 5 * 4 = 20 boxes.

Therefore, total 20 boxes are there.