Two forces of equal magnitudes act on a particle and they inclined an angle 'A'. If one of them is halved, the angle between the other and the original resultant is bisected by the new resultant. Show that 'A'=120⁰

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?