SOLUTION: Karla invests $1700 in one account and $1000 in an account paying 1 % higher interest. At the end of one year she had earned $199 in interest. At what rates did she invest?

Question 1150763: Karla invests $1700 in one account and $1000 in an account paying 1 % higher interest. At the end of one year she had earned $199 in interest. At what rates did she invest?
Found 2 solutions by VFBundy, greenestamps:
Answer by VFBundy(438) (Show Source): You can put this solution on YOUR website!
First account:
Principal = 1700
Rate = r
Interest = 1700r

Account with 1% higher interest:
Principal = 1000
Rate = r + 0.01
Interest = 1000(r + 0.01) = 1000r + 10

(1700r) + (1000r + 10) = 199

2700r + 10 = 199

2700r = 189

r = 0.07

First account:
Rate = r = 0.07

Account with 1% higher interest:
Rate = r + 0.01 = 0.07 + 0.01 = 0.08
Answer by greenestamps(13214) (Show Source): You can put this solution on YOUR website!

Here is an alternative way to set up the problem that can save a bit of time compared to the standard algebraic solution shown by the other tutor. Try it and see if you like it....

$1700 at one rate r, plus $1000 at a rate 1% higher, is equivalent to all $2700 at the rate r, plus on additional 1% on $1000 of the total. Then

ANSWER: The $1700 was invested at 7%; the $1000 was invested at 8%.

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