Math
posted by Martha .
Part of 26000 invested at 4% interest and the rest at 2% interest yields 680.00

Invested $X @ 4%.
Invested $(26,000  X) @ 2%.
0.04X + 0.02(26000  X) = 680,
0.04X + 520  0.02X = 680,
0.02X = 680  520 = 160,
X = $8000 @ 4%.
26000  8000 = $18000 @ 2%.