An example is 7 D in a W. The answer is 7 Days in a Week.
Another example is 64 S on a CB. The answer is 64 Squares on a CheckerBoard.
The one that has us stumped is:
10 GB on the W.
I'll confess, I think it may be 10 GB on a W, but whatever. Either way I still can't get it. Anyone?