You can have both, but chances are it's still going to eat into the other activity.
Business is just one thing you could do in the time not spent on advanced courses. It's nice to have the option but it also pressures students towards more curricular learning as opposed to self-motivated learning. For example you could spend 3 hours a day making iPhone apps, or spend that 3 hours studying. Chances are unless you become famous for your iPhone apps, those 3 hours acing your courses will seem more advantageous if you're college-oriented.
You'd be lucky if you're so well as off academically as to have free time and still ace courses.
