This will involve adding fractions then subtracting. 25% is equivalent to 1/4. So you'll be adding 1/4 + 1/3 + 1/8. To add fractions you'll need to find a common denominator. 3, 4, & 8 area all factors of 24. So convert your original fractions to 1/4= 6/24, 1/3= 8/24, & 1/8= 3/24. Add your numerators 6+ 8+ 3= 17 which you'll put over the denominator of 24= 17/24. the original question asks how many free hours does she have. their are 24 hours in a day so now you'll subtract 17 from 24. 24-17= 7. She has 7 hours free in a day.