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Question 1177782: An investor has 40000 dollars to invest. If part is invested at 7% simple interest rate and the rest at 11%, how much should at each rate to yield 8% simple interest on the total amount? Give the part, which is invested at the 7% interest rate
Answer by mananth(16946)   (Show Source):
You can put this solution on YOUR website! An investor has 40000 dollars to invest. If part ismple interest rate and the rest at 11%, how much should at each rate to yield 8% simple interest on the total amount? Give the part, which is invested at the 7% interest rate
Let x be invested at 7%
and y be invested at 11%
total yield = 8% = 8%*(x+y)
x+y =40000 ----------------1
7%x+11%y = 8% (x+y)
multiply by 100
7x+11y=8(x+y)
7x+11y=8x+8y
-x+3y=0 --------------------2
add 1 &2
4y=40000
y= 10000
x=30000
$30,000 is invested at the 7% interest rate
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