i'm currently a sophmore in high school but this year i only have 4 lawns but also just have a tractor (and i am a striping fanatic, has to be perfect)...but am talking parents into a zero turn so next season i am hoping to get more. My mom helps me push mow some at one yard which only really saves me 10 min. or so. As far as keeping your grades up...mow while there is day light, and study when it is dark.
Not much help probably..just my 2 cents