Sam invests $6000 in treasury notes and bonds. The notes pay 8% annual interest and the bonds pay 10% annual interest. If the annual interest is $550, how much is invested in bonds?

1 Answer
Aug 21, 2016

$3500 in bonds.

Explanation:

8% = multiply by 0.08

10% = multiply by 0.10

Let x be amount in notes and y be amount in bonds.

x + y = 6000

0.08x+0.10y = 550

Multiply the second equation by 10:

0.8x + y = 5500 implies y = 5500 - 0.8x

Substitute in for y in the first equation:

x+ (5500 - 0.8x) = 6000

0.2x = 500

Multiply both sides by 5:

x = 2500

implies y = 3500