I am still confused in how to answer this problem

Question

A mother wants to invest $8,000.00 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 earn 7%. If the total interest earned after one year is $480.00, how much money was invested in the CD account? 

Answer 1

Hi Natziely,

 

Lets's say that the amount of money in the CD account is x. that makes the amount of money in saving account is 8000-x.

 

Then we can have this equation

0.04x + 0.07(8000-x) = 480    //7%*1/100,      4%*1/100

0.07x + 320 -0.04x = 480

 

x = $2666.66 in in the CD account