Susan invests 2 times as much money at 8% as she does at 4% . If her total interest after 1 year is $800 , how much does she have invested at each rate?

Mathematics · College · Tue Nov 03 2020

Answered on

Let the money invested at 4% is x

Then, money invested at 8% be 2x

4% x + 8% (2x) = 800

4/100 x + 8/100 ×2x = 800

0.04x + 0.16x = 800

0.20x = 800

x = 800/0.20

x = 4000

So, money invested at 4% = $ 4000

And, money invested at 8% = 2 × 4000

= $8000