Question 119290
Given:
-	Julius can paint a house three times faster than Ruben.
-	they can paint a house in {{{4}}}{{{ days}}}
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Let Julius’ time be {{{x}}}, then Ruben’s time will be {{{3x}}}


{{{4/x + 4/3x =1}}}…..multiply both sides by {{{3x}}}


{{{4*3x/x + 4*3x/3x =1*3x}}}…..simplify


{{{4*3(cross(x))/cross(x) + 4*cross(3x)/cross(3x) =1*3x}}}…..


{{{12 + 4 = 3x}}}…..


{{{16 = 3x}}}…..divide both sides by {{{3}}}


{{{16/3 = cross(3)x/cross(3)}}}…..


{{{5(1/3) = x}}}…..or


{{{x = 5(1/3) }}}………. the faster painter will do the job alone in {{{5(1/3)}}} days