Question 1015372
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John mixed 3/4 liter of yellow paint with 1 1/4 liters of red paint to {{{highlight(make)}}} 2 liters of orange paint. To make a new batch of orange paint, 
he used exactly 1 liter of red paint. Using the same ratio, how many liters of yellow paint should John use to make his new batch of orange paint?
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Let us write {{{1}}}{{{1/4}}} as {{{5/4}}} for convenience.


Then your proportion is   {{{((3/4))/((5/4))}}} = {{{x/1}}},  which is the same as

{{{3/5}}} = {{{x/1}}}.


Now you can easily find the unknown amount of the yellow paint x: 


x = {{{3/5}}} liters.