Need to find the least number of big containers for the boxes I transfer - beyond solver?

[lumeipro]

Hi,

I need to find a way to find out the least number of shipping containers I need to transfer a group of boxes with different dimensions. For example,


A container can hold 40 cubic feet, and I have 100 small size boxes (2 cubic feet), 100 Medium (4 cubic feet)), and 100 Large (8 cubic feet). Assuming I can mix and match, What is the minimum number of containers I need to transport all 300 boxes?

I tried to use the solver, but the problem is it takes the aggregate sum in calculator, forgetting the fact that you can't split a box in two containers.

I appreciate on any thoughts...

Thanks,

Lumei