The wage elasticity of labor supply for women aged 18-25 is measured to be 0.3. Within this group, the average weekly wage of the high-school graduates is 2/3 the amount of college graduates. Assume that wage elasticity and all other individual characteristics (like intelligence, taste for work, networking skills, etc.) are the same across the education groups. If female college graduates offer 39 hours of work per week, what would be the quantity supplied of labor for female high school graduates? Midpoint formula should be used to calculate answer. Answer should be in hours per week.