Hello. How can I write one formula and drag it across a row so that it will add one row for each sum formula, for each column I move to the left with the formula.

Example:

=SUM(D41:D42)/SUM(C41:C42)
==SUM(E41:E43)/SUM(D41:D43)
=SUM(F41:F44)/SUM(E41:E44)

I want to drag the original formula across a row.