Answer:
12% is the mass percent of methanol in the solution.
Step-by-step explanation:
Mass of water = 100.0 g
Mass of NaCl = 10.0 g
Mass of methanol = 15.0 g
Mass of the solution = 100.0 g+ 10.0 g+ 15.0 g = 125.0 g
![Mass\%=\frac{\text{mass of compound}}{\text{Total mass of solution}}* 100](https://img.qammunity.org/2020/formulas/chemistry/high-school/sfibk7kv548es29jq3e8lbicjcczfiaj3p.png)
![Methanol\%=(15.0 g)/(125.0 g)* 100=12\%](https://img.qammunity.org/2020/formulas/chemistry/high-school/mew5o6cu1r1mtr684i7twf7r2apeczcphz.png)
12% is the mass percent of methanol in the solution.