Problema Solution
A chemist wants 20L of a 15% acid solution. She will mix a 5% solution with a 30% solution to obtain the mixture. How much of each should she use?
Answer provided by our tutors
let 'x' represent the amount in L of 5% solution used, then '20-x' represents the amount in L of 30% solutions used
0.15(20) = 0.05x + 0.30(20-x)
solving for 'x' we have x=12
20-12=8
12L of 5% solution should be mixed with 8L of 30% solution