Pls help me solve this

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?

60 2(x + 2) in the diagram, gef and hef are congruent. what is the value of x?

We have 339 ounces of jam to be divided up equally for 12 people how muny ounces will each person get