Question 350685
Let {{{A}}} be the amount of 10% solution and {{{B}}} the amount of 17%
solution. 
Volume equation:
1.{{{A+B=5}}}
Concentration equation:
2.{{{10A+17B=12(5)=60}}}
Multiply eq. 1 by -10 and add it to eq. 2,
{{{-10A-10B+10A+17B=-50+60}}}
{{{7B=10}}}
{{{highlight(B=10/7)}}}liters
Then from eq. 1,
{{{A+10/7=5}}}
{{{A=35/7-10/7}}}
{{{highlight(A=25/7)}}} liters