Question 127341
David has fourteen thousand dollars to invest and he invest nine thousand in a mutual fund that pays twelve per cent annual simple interest. If he wants to make at least twenty two hundred dollars in yearly interest, at what minimum rate does the remainder of the money need to be invested? 
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12% investment DATA:
Amount = 9000 dollars ; interest = 0.12(9000) = 1080 dollars
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x% investment DATA:
Amount:5000 ; interest 5000x dollars
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EQUATIOn:
1080 + 5000x >= 2200
5000x >= 1120
x >= 22.4%
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Cheers,
Stan H.