Answer:
15 liters of pure acid and 120 liters of 10% solution are needed.
Step-by-step explanation:
Let us assume that,
x = liters of pure acid ,
y = liters of 10% acid.
As we need a total of 135 liter of batch, so
[tex]x+y=135[/tex] ------------------------------1
As we need to make a batch of 20% acid solution, hence acid content of the mixture of two acids will be same as of the final one, so
[tex]x+0.1y=135\times 0.2=27[/tex] -----------2
Subtracting equation 2 for 1,
[tex]\Rightarrow x+y-x-0.1y=135-27[/tex]
[tex]\Rightarrow y-0.1y=108[/tex]
[tex]\Rightarrow 0.9y=108[/tex]
[tex]\Rightarrow y=120[/tex]
Putting this in the equation 1,
[tex]\Rightarrow x+120=135[/tex]
[tex]\Rightarrow x=135-120=15[/tex]
Therefore, 15 liters of pure acid and 120 liters of 10% solution are needed.
