C. 18.0g. all you really have to do is add both of them together and you get your answer.
Explanation:
Because when you move the decimal point once, it it equal to 10 and to convert in the metric system, you must multiply or divide by 10. For example, when converting 4 centimeters to millimeters, you can multiply by 10 to get 40 millimeters or you can move the decimal point to the right and add another 0 to get 40.
Use Raoult's Law:
Psolution = (χsolvent) (P°solvent)
24.90 = (x) (25.756)
x = 0.966765 (this is the solvent mole fraction)
χsolute = 1 - 0.966765 = 0.033235
χsolute = 0.03324 (to four sig figs)
Sorry I came a lil late,
The answer to your question is, 2.
Hope this helps! :)