Okay, so the final diameter of each scone is 9.6 cm; you could also find that by just multiplying 8 cm by 1.20 (120%).
And the area of the tray is 1400 SQUARE centimeters (not just cm). (Post #2 told you this.)
Now, as I've already said, I don't know what you are expected to do either, because I don't know what you are learning.
So please tell us what topics you have been studying, which may give us better ideas of what you are supposed to do. It's possible that this is just a very poorly planned exercise, since it is so unclear how you can do it mathematically; but we'll hope that it is intended to use some specific idea you were recently taught.