I solved the problem but am puzzling over something. The given code calls the addPrice() method twice, once on apple instance: apple.addPrice(50);, and once on apple2 instance: apple2.addPrice(100);. I am uncertain what exactly is going on here with the dot operator being used to call a static method on an instance of a class, as opposed to a Class itself, for example: Apple.addPrice();. If you substitute class name Apple in, instead of apple and apple2, the code works, and it seems clear to me why that does work--it is simply calling the addPrice method from Apple class. But I am not clear on exactly what is happening in the case of <object> dot < static method name>....the lecture did not cover this particular case.
apple.addPrice() vs. Apple.addPrice?