I use three columns. A, B and C.
In column C I have a formula every row `=A1*(1.6*B1)`

and then for the next row I have `=A2*(1.6*B2)`

in C2.

How can I do so I don't have to type in the new formula in column C for every row?

I use it in both Google Docs SpreadSheet and OpenOffice SpreadSheet.