Phyllis invested 69000 dollars, a portion earning a simple interest rate of 5 percent per year and the rest earning a rate of 7 percent per year. After one year the total interest earned on these investments was 4070 dollars. How much money did she invest at each rate? At rate 5 percent : At rate 7 percent : Solution let portion invested at 5 % = x and at 7% be y x+y = 69000 total interest = 5x+7y = 407000 x = 38000$ y = 31000$.

1. Phyllis invested 69000 dollars, a portion earning a simple interest rate of 5 percent per year and
the rest earning a rate of 7 percent per year. After one year the total interest earned on these
investments was 4070 dollars. How much money did she invest at each rate?
At rate 5 percent :
At rate 7 percent :
Solution
let portion invested at 5 % = x and at 7% be y x+y = 69000 total interest = 5x+7y =
407000 x = 38000$ y = 31000$