# Math Help - Interest words issues

1. ## Interest words issues

In one year, Carol earned the same amount of interest from an
investment at 8% annual interest as an investment at 12% annual
interest. She had invested $1500 more at 8%. How much money did she have invested 12%? Unknowns: x = amount invested at 8% y = amount invested at 12% First Eq: Interest from 8% = Interest from 12% x * (1 + 0.08) = y * (1 + 0.12) Second Eq: amount invested at 8% = amount invested at 12% +$1500

x = y + 1500

The second one is solved, I plug it into the fist one, Do that equation, and that makes the amount invested at 8% = 39k?

SO... After all the yada yada, the amount invested at12% = \$37,500?

No? or did I do something wrong?

Thanks

2. Originally Posted by Blakester
First Eq:

Interest from 8% = Interest from 12%

x * (1 + 0.08) = y * (1 + 0.12)
This is exceptionally clear and organized. Good work. I hated finding something wrong with it, it was so clean.

Anyway, what you have here is identical Account Balances, not identical Interest.

x * (0.08) = y * (0.12)

That will do it. Just equate the interest.

Give it another go.