Marianne borrowed $10,000 from three sources at different rates

[amd123]

Homework Statement

Marianne borrowed 10000. She borrows from a friend at 8%, twice that amount from her bank at 9% and the rest from her Insurance at 5%. She pays a total of 830 in interest for the first year. How much did she borrow from EACH SOURCE?!

Homework Equations

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The Attempt at a Solution

I tried on paper but got wrong values when i tried to see how much interest was from each source :(

 

[Mark44]

Show us what you tried.

And for the interest rates, what period are they over? And what sorts of things did she borrow 10000 of?

 

[rl.bhat]

Assume that she borrows 'x' amount from a friend, '2x' amount from her bank and rest from her insurance. Calculate interest paid for each amount for one year. Add it and equate it to 830. Solve for 'x'.