Question 1146352
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A chemist has 20% and 60% solutions of acid available. How many liters of each solution should be mixed to obtain 25 liters of 28% acid solution?
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v, unknown volume of 60%
M=25
M-v, unknown volume of 20%
L=20
H=60
T=28


{{{Hv+L(M-v)=TM}}}

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{{{Hv+LM-Lv=TM}}}
{{{Hv-Lv=TM-LM}}}
{{{(H-L)v=TM-LM}}}
{{{v=(TM-LM)/(H-L)}}}
{{{highlight(v=M((T-L)/(H-L)))}}}-----------------substitute, evaluate, then  use for evaluating M-v.