SOLUTION: A mother wants to invest​ $10,000.00 for her​ son's future education. She invests a portion of the money in a bank certificate of deposit​ (CD account) which earn

Algebra ->  Real-numbers -> SOLUTION: A mother wants to invest​ $10,000.00 for her​ son's future education. She invests a portion of the money in a bank certificate of deposit​ (CD account) which earn      Log On


   



Question 1127785: A mother wants to invest​ $10,000.00 for her​ son's future education. She invests a portion of the money in a bank certificate of deposit​ (CD account) which earns​ 4% and the remainder in a savings bond that earns​ 7%. If the total interest earned after one year is​ $600.00, how much money was invested in the CD​ account?
Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!


The $600 interest is a return of 6% on the $10,000 that was invested.

6% is two-thirds of the way from 4% to 7%; that means 2/3 of the money was invested at the higher rate.

The question asks for the amount invested in the CD account, which is the lower rate; 1/3 of the money was invested there.

ANSWER: 1/3 of the $10,000, or $3,333.33, was invested in the CD account.

For a traditional algebraic solution (which will require much more work and take much longer, solve the equation that says amount x invested at 4%, plus (10000-x) invested at 7%, yields $600 interest:

%28.04%29%28x%29%2B%28.07%29%2810000-x%29+=+600

You can finish the slow algebraic solution.