Solving a Word Problem: Preparing Special Eye Drops

[Zed]

Word problem !

Hi ,

This is a Hw question i have am stuck on i don't know how to solve it ...

A pharmacist is to prepare 16 milliliters of special eye drops for a glaucoma patient. The eye-drop solution must have a 5% active ingredient, but the pharmacist only has 10% solution and 1% solution in stock.


How much of 10% solution should be used to fill the prescription?

How much of 1% solution should be used to fill the prescription?


please help

thx

 

[Alkatran]

convert to formulas:
The amount of active solution in each ingredient should sum to the total active solution:
x*.1 + y*.01 = 16*.05
The amount of each ingredition should sum to the total amount:
x + y = 16

Then solve.