Question 1096495
Let A be the amount of 10% water and B the amount of 25% water.
1.{{{A+B=10}}}
and
{{{ 10A+25B=20(A+B) }}}
{{{10A+25B=20(10)}}}
{{{10A+25B=200}}}
2.{{{2A+5B=40}}}
From 1,
{{{2A+2B=20}}}
{{{2A=20-2B}}}
Substituting into 2,
{{{(20-2B)+5B=40}}}
{{{3B=20}}}
Solve for B, then use either equation to solve for A.