SOLUTION: A doctor perscribes an ointment that is 2% hydrocortisone. A pharmacist has 1% and 5% concentrations in stock. How many ounces of each should the pharmacist use to make 1-ounce tub

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A doctor perscribes an ointment that is 2% hydrocortisone. A pharmacist has 1% and 5% concentrations in stock. How many ounces of each should the pharmacist use to make 1-ounce tub      Log On


   

Question 274897: A doctor perscribes an ointment that is 2% hydrocortisone. A pharmacist has 1% and 5% concentrations in stock. How many ounces of each should the pharmacist use to make 1-ounce tube?
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
.05x+.01(1-x)=.02*1
.05x+.01-.01x=.02
.05x-.01x=.02-.01
.04x=.01
x=.01/.04
x=.25 ounces of the 5% ointment is used.
1-.25=.75 ounces of the 1% ointment is used.
Proof:
.05*.25+.01*.75=.02*1
.0125+.0075=.02
.02=.02