simple interest

Question

i need to make sure i set this up correct

 

nico is saving money for his college education, he invest some money at 6% and 1300 less than that amount at 5% the investment produced a total of 144 interest in 1 year how much did he invest at each rate

Answer 1

Hi Brent

 

Let I be the amount of money invested, then we can calculate the interest using the information given

 

Ix(.06) +(I-1300)x.05 = 144 so we have .06I + .05I -65 =144, solving for I gives I = 1900.

 

Interest from the first investment =.06x $1900=$114

Interest from the 2nd investment = .05($1900-$1300)= $30 and together they add to $114 + $30 =$144.

 

Regards

Jim S

 

Answer 2

 X - amount invest in 6%

 

 X - 1300 - amount invests in 5 %

 

  X ( 0.06 ) + ( X - 1300) 0.05 = 144

 

    X ( 0.06 + 0.05) = 1300 * .05 + 144

 

     X ( 0.11) = 209

 

    X = 209/ 0.11 = $1900  / invested in 6%

 

    $ 1900 - 1300 = $ 600 / invested in 5%