Question

A chemist mixes a 10% hydrogen peroxide solution with a 25% hydrogen peroxide solution to create 30 liters of a 15% hydrogen peroxide solution. How many liters of the 10% solution did the chemist use to make the 15% solution?

Answer 1

System of equations problem, set up two equations and then find their intercept.

Answer 2

First equation will be from:
A chemist mixes a 10% hydrogen peroxide solution with a 25% hydrogen to create a 15% hydrogen peroxide solution

Second equation will be from:
A chemist mixes two solutions to make 30L of final solution

Set up two variables:

x = litres of 10% H2O2 mixed
y = litres of 15% H2O2 mixed

Answer 3

I got 20

Answer 4

you are correct.

Answer 5

http://www.wolframalpha.com/input/?i=0.1x+%2B+0.25y+%3D+0.15%28x%2By%29%2C+x+%2B+y+%3D+30

Answer 6

if you want to check your answer

Answer 7

20L of x and 10L of y