Question 160150
Let T be the volume of 30% solution, F be the 50% solution.
Total volume
1.{{{T+F=50}}}
Total concentration
2.{{{0.30T+0.50F=0.42(50)}}}
2.{{{30T+50F=2100}}}
Multiply eq.1 by -30 and add to eq. 2 and solve for F,
{{{-30T-30F+30T+50F=-1500+2100}}}
{{{20F=600}}}
{{{highlight(F=30)}}}
From 1,
1.{{{T+F=50}}}
{{{T+30=50}}}
{{{highlight(T=20)}}}
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20mL of 30% solution, 30 mL of 50% solution.