Rico invests some of his savings at 3 percent per year & an equal amount at 5 percent per year. His income totals 1,800 a year. How much did Rico invest at each rate?

1 Answer
Feb 17, 2017

$22,500 at each rate.

Explanation:

The interest is earned over one year, so it does not matter whether it is invested at simple or compound interest.

Let the amount of money at each rate be x

SI=PRT100

x×3×1100+x×5×1100=1800

Multiply by 100 to cancel the denominators.

100×x×3×1100+100×x×5×1100=100×1800

3x+5x=180,000

#8x = 180,000)

x=$22,500