A chemist wants to mix a solution of 20% chlorine with a solution of 60% chlorine to make 120 liters of 30% solution of chlorine. How many liters of each chlorine solution should she mix?

90 and 30 liters

Step-by-step explanation:

1) if solution of 20% is 'x' and of 60% is 'y' liters, then

2) the pure chlorine is: for solution of 20% - 0.2x, for solution of 60% - 0.6y and

3) the mix of the two solutions is 120=x+y.

4) using these items it is possible to make up the system of two equations:

5) finally, x=90 liters of 20%; y=30 liters of 60% solution.

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