A bank loaned out 23,000, part of it at the rate of 3% annual interest, and the rest at 12% annual interest. The total interest earned for both loans was 2,400.00. How much was loaned at each rate?

Answer 1

2400/23000 = about 10.4% which is much closer to 12% than 3%, so most of the investment is at 12%

(12-3)/(12-10.4) = 9/1.6 = about 5.6

x/(23000-x) = about 5.6

23000(5.6) -5.6x = x

6.6x = 128800/6.6= roughly$19520 invested at 12%

2300-1952 =roughly $3480 invested at 3%

approximately

solve the following for the exact amounts

.12x + .03(23000-x) = 2400

.09x =2400-23000(.03) = 2400-690= 1710

x=1710/.09= $19,000 invested at 12%

23000-19000= $4000 invested at 3%