Problema Solution
Phyllis invested $10,000, a portion earning a simple interest rate of 7 1/4
% per year and the rest earning a rate of 7% per year. After 1 year the total interest earned on these investments was $722.5. How much money did she invest at each rate?
Answer provided by our tutors
let
x = the money invested at a rate of 7 1/4 = 7.25%
y = the money earning a rate of 7% per year
Phyllis invested $10,000:
x + y = 10000
After 1 year the total interest earned on these investments was $722.5:
0.0725x + 0.07y = 722.5
by solving the system of equations:
x + y = 10000
0.0725x + 0.07y = 722.5
we find:
x = $9,000
y = $1,000
click here to see the step by step solution of the system of equations:
Phylis invested $9,000 at 7 1/4 per year and $1,000 at 7% per year.