A cell phone company offers two plans for minutes. Plan A: $15
per month and $2
for every 300 texts.
Plan B: $25
per month and $0.50
for every 100 texts.
How many texts would you need to send per month for plan B to save you money?

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?