Answer:
Elena invested $ 1,700 at 5%, $ 700 at 4%, and $ 600 at 3%.
Step-by-step explanation:
Given that Elena receives $ 131 per year in simple interest from three investments totaling $ 3000, and part is invested at 3%, part at 4% and part at 5%, and there is $ 1000 more invested at 5% than at 4%, to find the amount invested at each rate, the following calculations must be performed:
1500 x 0.05 + 500 x 0.04 + 1000 x 0.03 = 75 + 20 + 30 = 125
1600 x 0.05 + 600 x 0.04 + 800 x 0.03 = 80 + 24 + 24 = 128
1700 x 0.05 + 700 x 0.04 + 600 x 0.03 = 85 + 28 + 18 = 131
Therefore, Elena invested $ 1,700 at 5%, $ 700 at 4%, and $ 600 at 3%
To find which ratio is higher, we can first convert the ratios into fractions (that makes it easier, at least for me) and then simplify the fractions and see which one is greater.
Since ratios are basically division, 15:20 =
, and
12:16 = 
Now we simplify these fractions. 15 and 20 have a GCF of 5, so taking out the common number gives us the simplified fraction of
.
12 and 16 have a GCF of 4, so taking out the common number gives us the simplified fraction of
. Since
=
, these ratios are the same.