Stan invested $32,000, part at 6% and part at 5%. If the total interest at the end of the year is $1,770, how

Question

Stan invested $32,000, part at 6% and part at 5%. If the total interest at the end of the year is $1,770, how much did he invest at 6%?

Answer 1

Let A = amount invested at 6%
32000 - A = amount invested at 5%

Interest = rate x principal

0.06A + 0.05(32000 - A) = 1770

0.06 A + 1600 - 0.05A = 1770

0.01 A = 170

A = 17,000

$17,000 invested at 6%
$15,000 invested at 5%

that's it! :)

Answer 2

6%x + 5%(32000 -- x) = 1770
=> 1%x = 1770 -- 5%32000 = 1770 -- 1600 = 170
x = $170*100 = $17000
invested $17000 @ 6%.

Answer 3

0.06x + 0.05(32000-x) = 1770
6x + 160000 - 5x = 177000
x = 17000