Question 348666
Let {{{A}}} be the amount of 20% acid solution. 
Let {{{B}}} be the amount of 35% acid solution. 
Volume:
1.{{{A+B=25}}}
Concentration:
{{{20A+35B=26(25)}}}
2.{{{4A+7B=130}}}
Multiply eq. 1 by 4 and subtract from eq. 2,
{{{4A+7B-4A-4B=130-100}}}
{{{3B=30}}}
{{{highlight( B=10)}}}liters
From eq. 1,
{{{A+10=25}}}
{{{highlight( A=15)}}}liters