Explain why the arithmetic sequence: 1,14,27,40 contains many terms of the form etc where only digit two appears. how many 2's appear in the sequence? (the nth term rule is 13n-12)

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?