Assignment:
A CE graduate student named Naresh is experimenting with large concrete block sizes. For a block size of 1 foot high by 1 foot wide by 3 feet long, he tries to pack as many blocks as possible into a 7 foot by 7 foot by 7 foot metal box. He soon realizes that it is impossible. There will always be a 1 foot by 1 foot by 1 foot gap somewhere. In how many ways can this gap be in the interior of the blocks and not on an outside surface?
Provide complete and step by step solution for the question and show calculations and use formulas.