. writing inequalities from word problems

2 ANSWERS

1. Guest4580
   

   You will make N copies per year, therefore in four years you make M=4N copies. Now, using the photocopy service, copies made over four years will cost you
   
   $_service = Number * cost per page = M * 0.09 = 0.09M
   
   Buying a copier costs $_copier = 2750, and making your own copies over the four year period will obviously cost
   
   $_owncopies = M * 0.04 = 0.04M
   
   So you want the total cost of buying a copier and making your own copies to be less than if you had made that SAME amount of copies elsewhere, thus
   
   $_copier + $_owncopies < $_service
   2750     + 0.16N        < 0.36N
   or
   2750     + 0.04M        < 0.09M
   
   As M is the minimum number of copies to be made during four years to make buying the copier feasible, we solve for M as
   
   2750 < 0.09M - 0.04M
   2750/(0.05) < M
   
   M > 55000 copies in four years

   Report (0) (0)  |   12 years, 8 month(s) ago  

2. Guest6536
   

   A wedding cake costs $550, and the catering price per person is $25. Up to how many persons may attend on a $3500 budget?

   Report (0) (0)  |   12 years, 8 month(s) ago