3,540 grams of ash
If its density is 2.75 g/cc and
density = mass / volume then its volume is
volume = mass / density
volume = 3,540 g / 2.75 g / cc
volume =
1287.272727 cc
So, rounded it is 1,287.3 cubic centimeters but to keep the same number of significant figures, the volume is
volume =
1,287 cc