Question

Nico is saving money for his college education. He invests some money at 9% and $1400 less than that amount at 3%. The investments produced a total of $198 interest in 1 yr. how much did he invest at each rate?

Answer 1

Let x = the amount of money he invests at 9%
and y = the amount of money he invests at 3%

y = x - 1400
0.09x + 0.03y = 198

x - y = 1400
9x + 3y = 19800

3x - 3y = 4200
9x + 3y = 19800

12x = 24000
x = 2000
y = 600

$2000 invested at 9% interest
and $600 invested at 3% interest.