You want to meal prep to save time. The total amount of time you need to prepare all the dishes is 5 hours. You only want to cook hour a day. How many days will you spend meal prepping?

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?