Question 340409
Let A be the amount of 30% solution, B the amount of 80% solution.
1.{{{A+B=50}}}
.
.
.
{{{30A+80B=60(50)}}}
{{{30A+80B=3000}}}
2.{{{3A+8B=300}}}
Multiply eq. 1 by (3) and subtract it from eq. 2,
{{{3A+8B-3A-3B=300-150}}}
{{{5B=150}}}
{{{highlight(B=30)}}}cc
Then from eq. 1,
{{{A+30=50}}}
{{{highlight(A=20)}}}cc