calculate the mass/volume percent of a NaCl solution in which 127g of NaCl is dissolved in enough water to give a total volume of 2.69L.

Answer 1

Didn't I do one like this for you last evening? What do you not understand about this. If you know the definitions you should be able to do this.
mass % = [(g solute/g solution)]*100
Also, is that mass% and volume% as in two separate problems?

Answer 2

4.72