Answer:
65%
Explanation:
-Given the mass of the solute, sugar is 255 g and of the solvent, water is 135g.
-We apply the percent by mass formula as below:
[tex]\%\ By \ mass=\frac{Mass \ of \ solute}{Mass \ of \ solution}\times 100\\\\=\frac{255\ g}{255\ g+135\ g}\times 100\\\\=65.38\%\\\\\approx 65\%[/tex]
Hence, the mass percent is 65%