MathRevolution wrote:
Company A has x mailing lists and Company B has y mailing lists. If the total mailing lists’ number combined Company A and Company B is equal to 3 times the mailing lists’ number of Company A, what is the number of mailing lists that both Company A and Company B have, in terms of x and y?
A. 2x-y
B. y-2x
C. 3x+y
D. y+2x
E. y-3x
\(?\,\, = {\rm{both}}\,\,\, = \,\,\,f\left( {x,y} \right)\)

\(x + y - {\rm{both}} = 3x\,\,\,\,\,\,\left[ {\,{\rm{simplifier}}\,} \right]\,\,\,\,\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\,\,\,\,?\,\, = \,\,y - 2x\,\,\,\,\,\)
This solution follows the notations and rationale taught in the GMATH method.
Regards,
Fabio.
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Fabio Skilnik :: GMATH method creator (Math for the GMAT)
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