<PRE><B>Question 1204800</B>
One acetic acid solution is 70% water and another is 30% water. How many liters of each solution should be mixed to produce 20 liters of a solution that is 60% water? Solve using system of equations 

One acetic acid solution is 70% water let the quantity be x liters
another is 30% water Let quantity be y liters

We need 20 liters of acid in final mix
x+y=20-----------------------(1)

water percentage equation. 60% water  in 20 liters= 12 liters

0.7x+0.3y= 12-----------------------(2)
multiply by 10
7x+3y= 120
3x+3y=60 (1) multiplied by 3. subtract
4x=60
x=15
Therefore y=5
Check

 15+5=20

0.7*15+5*0.3= 12

15 liters of the 70% water acid and 5 liters of the 30%  water  acid  are added

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