dabaobao wrote:
Shawna and Jia worked EACH ONE ALONE to paint a house. Combined they worked for a total of y hours. Before the job started, Shawna paid t dollars to purchase paint and other supplies for the job. When the job was completed, Shawna was given a total of d dollars to pay for the work as well as reimburse her for the supplies. If Shawna worked for x more hours than Jia, how much money should Shawna give to Jia such that Shawna and Jia are each paid the same hourly rate for their work?
Very nice approach,
pandeyashwin !
Without exploring a particular case (as I did previously), let´s show the "GMATH´s way", using
UNITS CONTROL, one of the most powerful tools of our method!
\(?\,\,\,\,:\,\,\,\,{\rm{Jia}}\,\,{\rm{fair}}\,\,\$ \,\,{\rm{payment}}\,{\rm{for}}\,\,{\rm{her}}\,\,{\rm{work}}\,\,\,\,\,\,\,\,\left[ {\,\$ \,c\,\,\, = \,\,\,{\rm{common}}\,\,{\rm{hourly}}\,\,\,{\rm{rate}}\,} \right]\,\,\,\)
\(y\,\,{\rm{h}}\,\,\,\left\{ \matrix{
\,{\rm{Shawna}}\,\,:\,\,\left( {{y \over 2} + {x \over 2}} \right)\,\,{\rm{h}} \hfill \cr
\,{\rm{Jia}}\,\,:\,\,\left( {{y \over 2} - {x \over 2}} \right)\,\,{\rm{h}} \hfill \cr} \right.\,\,\,\,\,\,\,\left[ {\,{\rm{Sum}}\,\,y\,\,,\,\,\,x\,\,{\rm{difference}}\,\,{\rm{,}}\,\,{\rm{Shawna}}\,\,{\rm{more}}\,\,{\rm{time}}\,} \right]\)
\(\left( {{{y + x} \over 2}} \right)\,\,{\rm{h}}\,\, \cdot \,\,\left( {{{\,\$ \,\,c\,} \over {1\,\,{\rm{h}}}}} \right)\,\,\,\,\, + \,\,\left( {{{y - x} \over 2}} \right)\,\,{\rm{h}}\,\, \cdot \,\,\left( {{{\,\$ \,\,c\,} \over {1\,\,{\rm{h}}}}} \right)\,\,\,\, = \,\,\,\,\$ \,\,\left( {d - t} \right)\,\,\,\,\,\,\, \Rightarrow \,\,\,\,\,yc = d - t\,\,\,\,\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\,\,c = {{d - t} \over y}\,\,\,\,\,\left[ {\rm{$}} \right]\,\)
\(?\,\,\, = \,\,\,\,\left( {{{y - x} \over 2}} \right)\,\,h\,\,\, \cdot \,\,\,\left( {{{\,\$ \,\,\left( {d - t} \right)\,} \over {y\,\,\,{\rm{h}}}}} \right)\,\,\,\,\, = \,\,\,\,{{\,\left( {y - x} \right)\left( {d - t} \right)\,} \over {2y}}\,\,\,\,\,\,\left[ {\rm{\$ }} \right]\)
This solution follows the notations and rationale taught in the GMATH method.
Regards,
Fabio.
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