Stationary bike, treadmill, or the elliptical?

[mileyfan_22]

Which one is better to burn calories? and i do have problems with my knees. all i can do in all is like 30 minutes of exercise, that's the only time i have, what should i do? thanks. Best answer rewarded.

 

[jayjay]

Elliptical is the best. But anyone would be better than nothing.