Models and Applications

Question

A bank loaned out $19,500, part of it at the rate of 5% annual interest, and the rest at 15% annual interest. The total interest earned for both loans was $2,775.00. How much was loaned at each rate?

$_________=was loaned at 5% and

$_________=was loaned at 15%.

Answer 1

.15x + .05(19.5-x)=2.775

.10x= 2.775-.975=1.8

x=18 = $18,000 at 15%

$1,500 at 5%

check the answers

.15(18)=2.7

.05(1.5)=.075

.075+2.7=2.775 = $2,775

18/1.5= 12 times as much invested at 15% as at 5%

2775/19500 = 111/780= about 14.23% average return

15-14.23= 0.77

14.23-5= 9.23

9.23/,77 = about 12