Magician:
The air resistance would be the same for a same size ping pong ball no matter what weight difference.
It's not correct, air resistance/drag also depends on speed,
But what does that have to due with a objects weight? Two ping pong balls will drop at the same speed regardless of weight difference so their air resistance/drag AND speed will be the same.
Isaac Newton would be doing a face palm if he was following this thread. 
Lefty