thinking about my job

I went back to home late last night because my students asked me to extend the time for tutoring since they will have the semester exam today. I arrived at home around 10:30pm and noticed the mail from another student. He asked some questions of math. The questions are very easy besides I taught him how to solve over again and again. Seem he still can't understand them.:-(
Anyway, I am getting very busy these days with tutoring compared to the importing company at the daytime. Maybe I'd better have job only as a tutor on concentrate. I tried to calculate the amount of my benefits when I have 2 times of students I have currently. Oh, I can expect gain pretty much.