Question 1036937
Paul has $80,000 to invest. His intent is to earn 15% interest on his investment. He can invest part of his money at 6% interest and part at 18% interest. How much does Paul need to invest in each option to make a total 15% return on his $80,000? 
Quantity:: s + e = 80,000
Interest:: 0.06s + 0.18e = 0.15*80,000
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Modify for elimination:
6s + 6e = 6*80,000
6s + 18e = 15*80,000
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Subtract and solve for "e":
12e = 9*80,000
e = (3/4)(80,000)
e = $60,000 (amt. to invest at 18%)
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Solve for "s"
s = 80,000 - e = 80,000-60,000 = $20,000 (amt. to invest at 6%)
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Cheers,
Stan H.
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