Question 335410
Let A be the amount of 60% solution, B the amount of 25% solution.
1.{{{A+B=168}}}
.
.
.
{{{60A+25B=50(168)}}}
{{{60A+25B=8400}}}
2.{{{12A+5B=1680}}}
From eq. 1,
{{{A=168-B}}}
Substitute into eq. 2,
{{{12(168-B)+25B=1680}}}
{{{2016-12B+5B=1680}}}
{{{-7B=-336}}}
{{{highlight(B=48)}}}ml
Then from eq. 1,
{{{A+48=168}}}
{{{highlight(A=120)}}}ml