Question 881128
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Hi
Let x represent the number of books {{{x+15}}} the number of pamplets
.5x + .15(x+15) = $90
      .65x = 90-2.25 = 87.75
         x = 135, number of books.  150 pamplets {{{135 + 15}}}
CHECKING our answer***
{{{.5*135 + .15*150 = 67.50 + 22.50}}} = $90
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