Cherry pie would cost 11 dollars a piece
Pumpkin pie would cost 20 dollars a piece
Arjun sold one more pumpkin pie then Huong, and the same amount of cherry pies. With this information, one may conclude 197-177 will give price of pumkin pie, which would be 20 dollars a piece. Then multiply that by 6 to get 120 then subtract 197-120 to get 77 then divide that by 7 to get 11 dollars a piece for cherry pie.