Preparing is the correct answer
I would oppose it. Studies show teens biological clocks naturally want to go to bed later and wake up earlier. By making school and hour earlier this makes teens more groggy especially because their bodies do not want to go to sleep earlier so this can cause sleep deprivation which will make school work less concentrated and makes teens attitudes about school worsen.
The least common denominator of them is 75:
15, 30, 45, 60, 75, 90, ...
25, 50, 75, 100, ...
Five fifteens fit in 75 and three twenty-fives fit in 75, so we have to multiply the first fraction by 5 and the second one by 3:
10/75
12/75
It means that the second one is bigger by 2/75.
Is this a question if so you could find it online
