Rachel runs her own hot dog stand on the U of A campus. The monthly cost of the cart rental and business permit is $600. Rachel's contribution margin is $1.50 per hot dog sold. She has recently added individual servings of potatos chips to her product offering. Each bag of potato chips has a contribution margin of $0.75 per bag. Rachel sells 5 bags of potato chips for every 10 hot dogs. How many total units much Rachel sell in a month to earn a target monthly profit of $1,200