One year is 52 week, days of work is 5, 5*52 week is 260 days. One year salary is 28,612, use 28,612/ 260 =110.05 a day. If the boy works only one day a week the he only work 52 day in a year, so is 52*110.05=5722.4 for the boys.
Then use 28612-5722.4= 22889.60 is the girls salary