At the market you spent $21 for 5 bags of chips and 3 bottles of mango juice. Your buddy spent $12 for 2 bags of chips and 3 bottles of mango juice. How much does each item cost?

Acertain drug is made from only two ingredients: compound a and compound b. there are 3 millimeters of compound a used for every 4 millimeters of compound b. if a chemist wants to make 693 milliliters of the drug, how many milliliters of compound a are needed?