Question 618385
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Hi,
How much pure antifreeze{{{x}}} must be added to 12 gallons of
 20% antifreeze to make a 40% antifreeze solution?            
            antifreeze = antifreeze
{{{ x + .20*12 = .40(12+x)}}}
 {{{.60x = .20*12}}}
 {{{ x = .20*12/.6}}}
  x = 4 gal
One computer printer can print a company's mailing labels in
 40 minutes..A second printer in 60 minutes   
Time {{{x}}}Togeiher: PER min KEY
 1/40 + 1/60 = 1/x
  60x + 40x = 2400   
    100x = 2400    |Multiplying thru by 2400x so as all denominators = 1
       x = 24 min