Please answer this correctly

(60 points) explain this in detail

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?

Me answer this question: -2/3p + 1/5 - 1 + 5/6p i think the simplified expression is 1/6p - 4/5 correct me if i'm wrong, and explain it! if i have it right, just tell me. you so