Problema Solution

100% acid solution is to be added to 10% solution to give us 117L of 20% acid

Answer provided by our tutors

Let 'x' represent the amount of 10% solution:

117*0.2=0.1(117-x)+x

click here to solve for x

x=13

117-13=104

So 104L of 100% acid solution is added to 13L of 10% in order to make 117L of 20% acid solution.