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| Question 881946:  A university invests $600,000 at simple interest, part at 6%, half that amount at 4.5%, and the rest at 3.5%. What is the most that the university can invest at 3.5% and be guaranteed $24,600 in interest per year?
 Answer by lwsshak3(11628)
      (Show Source): 
You can put this solution on YOUR website! A university invests $600,000 at simple interest, part at 6%, half that amount at 4.5%, and the rest at 3.5%. What is the most that the university can invest at 3.5% and be guaranteed $24,600 in interest per year? ***
 let x=amt invested at 4.5%
 2x=amt invested at 6%
 600,000-3x=amt invested at 3.5%
 ..
 4.5%x+6%2x+3.5%(600,000-3x)=24,600
 .045x+.12x+21000-.105x=24600
 0.06x=3600
 x=60000
 600000-3x=420000
 most that the university can invest at 3.5% = $420,000
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