Question 279075:  how much soap is needed to make 10 liters of a 20% soap solution 
 Answer by oberobic(2304)      (Show Source): 
You can  put this solution on YOUR website! Volume = 10 liters 
Desired solution is 20% soap, so we assume that 80% is pure water. 
Assuming we are measuring volumes, then the amount of pure soap in 10 liters of 20% soap is .2*10 = 2 liters of pure soap. 
That means we add 8 liters of pure water to arrive at 10 liters. 
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