67 boxes are 6m by 5m by 3m what will the total volume be needed in the storage area?
6*5*3*67 = 6030
So you will need at least 6030 m^3 of storage. But you will probably need more because the boxes have to fit without being crushed.
If they were in a straight snake that was 67 boxes long then it would be exactly 6030m^3