Acontainer of oregano is 17 pounds heavier than a container of peppercorns their total weight is 253 pounds the peppercorns will be sold and 1 ounce bags how many bags of peppercorns can be made

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?