I need help with this math equation!!!!!?
a man has $10,000 to invest, from which he wishes to earn an annual income of $13,000 interest per year. He decides to invest part of his money in a money market at 10% interest, and the remainder in stock at 15% interest. How much should he invest at each rate?…..The answers are $4000 and $6000….any idea how to get those answers?? and is there any tips u can give me to help out how to figure out any kind of word promblems? they just confuse me like crazy!!!!!
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Firstly, I think you mistyped that, was the interest really 13,000 or was it 1,300. Assuming you meant 1,300 (since 13,000 isn’t possible) you would use a system of equations.
First, to make sure the two numbers add to 10,000:
a + b = 10,000
Second to make sure the interest works out to 1,300 (.1 = 10%, .15 = 15%):
(a * .1) + (b * .15) = 1300
Then solve the first for a:
a = 10,000 – b
And substitute that into the second:
((10,000 – b) * .1) + (b * .15) = 1,300
Solve:
1000 – .1b + .15b = 1,300
1000 + .05b = 1,300
.05b = 300
b = 6000
Then you can solve for a:
a + 6000 = 10,000
a = 4000
And since we used (a * .1) and (b * .15), a is what you invest at 10% and b is what you invest at 15%.
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