SOLUTION: A chemist has some 8% hydrogen peroxide solution and some 3% hydrogen peroxide solution, how many milliliters of each should be used to make 500-milliliter solution that is 4%?

Question 301657: A chemist has some 8% hydrogen peroxide solution and some 3% hydrogen peroxide solution, how many milliliters of each should be used to make 500-milliliter solution that is 4%?
Found 2 solutions by richwmiller, josmiceli:
Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!
x+y=500
8/100*x+3/100*y=500*4/100
x=100 y=400

Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = ml of 8% solution needed
Let = ml of 3% solution needed
given:
hydrogen peroxide in 8% solution:
ml
hydrogen peroxide in 3% solution:
ml
-----------------

(1)
and
(2)
Multiply both sides of (2) by
and subtract (2) from (1)
(1)
(2)

and, since

100 ml of 8% solution and 400 ml of 3% solution are needed
check:

OK

RELATED QUESTIONS
A hair dye is made by blending a 8% hydrogen peroxide solution and a 3% hydrogen peroxide (answered by checkley77)
A hair dye is made by blending a 8% hydrogen peroxide solution and a 3% hydrogen peroxide (answered by greenestamps)
A hair dye is made by blending a 9% hydrogen peroxide solution and a 3% hydrogen peroxide (answered by Alan3354,josgarithmetic)
A hair dye is made by blending a 7% hydrogen peroxide solution and a 4% hydrogen peroxide (answered by ptaylor)
How many milliliters of a 18% hydrogen peroxide solution and how many milliliters of a... (answered by josgarithmetic)
How many milliliters of a 25% hydrogen peroxide solution and how many milliliters of a 9% (answered by lwsshak3)
how many milliliters of a 10% hydrogen peroxide solution and how many milliliters of a 2% (answered by stanbon,Alan3354)
How many pints of 1% hydrogen peroxide peroxide solution should be mixed with 4% hydrogen (answered by addingup)
want to make 12 liters of a 40% hydrogen peroxide solution consisting of a combo of 70% (answered by checkley79)