<PRE><B>Question 391191</B>
Let {{{a}}} = L of 85% solution to be added
{{{.85a}}} = L of additive 
given:
{{{.45*5 = 2.25}}} L of additive in 45% solution
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In words:
(L of additive)/(L of solution) = 60%
{{{(.85a + 2.25)/(a + 5) = .6}}}
{{{.85a + 2.25 = .6*(a + 5)}}}
{{{.85a + 2.25 = .6a + 3}}}
{{{.25a = .75}}}
{{{a = 3}}}
3 Liters of 85% solution should be added
check:
{{{(.85a + 2.25)/(a + 5) = .6}}}
{{{(.85*3 + 2.25)/(3 + 5) = .6}}}
{{{(2.55 + 2.25)/8 = .6}}}
{{{4.8/8 = .6}}}
{{{4.8 = 4.8}}}
OK</PRE>