A word problem using two variables such as x and y.?

Question

A pharmacist is to prepare 15 milliliters of special eye drops for a glaucoma patient. The eye-drop solution must have a 2% actice ingredient, but the pharmacist only has 10% solution and 1% solution in stock. She must use these solutions to produce the finl prescription. Can the pharmacist use the solutions she has in stock to fill the prescription? If she can, show the amout (volume in milliliters) of the 10% solution and the 1% solution that she would use to fill the prescription.

Please teach me how to solve this and explain throughly using two variables, such as x and y.

Answer 1

Use CV=C1V1 + C2V2
CV=C1(15-V2) + C2V2
The rest should be easy to solve.

Answer 2

no