Sam invested $2150, part of it at 6% and the rest at 8% yearly interest. The yearly income on the 8% investment was $42 more than twice the income from the 6% investment.

Question

How much did he invest at each rate?

investment at 6%	$
investment at 8%	$

Answer 1

X is the amount invested at 6%

Y is the amount invested at 8%

X+Y = 2150

0.08Y = 2(0.06X ) + 42

0.08Y = 0.12x + 42

0.08Y = 0.12 ( 2150-y) + 42

0.08y = 258 - 0.12y + 42

0.2Y = 300

2Y = 3000

Y = 1500

x = 2150 - y = 2150 - 1500 = 650

CHECK

0.06X = 0.06*650 = 39

0.08*1500 = 120

2(39) + 42 = 78+42 = 120

1500 invested at 8%

650 invested at 6%