When 18 boys joined a group of y students, the ratio of boys to girls in the group became 4: 5. write an algebraic expression for the number of girls in terms of y.

Me its important ! marge runs an ice cream parlor. her speciality is triple chocolate sundaes. she can prepare 1 sundae every 2 minutes, and she earns $1.20 for each sundae she makes . if she just makes sundaes for a single shift of at most 4 hours and at least 2 hours , which function relates her earnings to the number of minutes she works?