Phyllis invested 45000 dollars a portion earning a simple in

Phyllis invested 45000 dollars, a portion earning a simple interest rate of 4 percent per year and the rest earning a rate of 6 percent per year. After one year the total interest earned on these investments was 2380 dollars. How much money did she invest at each rate? At rate 4 percent : At rate 6 percent :

Solution

Let x amount invested at 4%

Interest for 1 year = x*4*1/100

= 0.04x

Remaining 45000-x is invested at 6%

Interest after 1 year = (45000 -x)6*1/100

= 2700 -0.06x

Total ineterst after 1 year = 2380

So, 0.04x +2700 -0.06x = 2380

- 0.02x = -320

x = $ 16000 @ 4 % rate

45000 -x = $29000 @ 6% rate