Answer:
Amount invested at 4% is $14,000
Amount invested at 7% is $10,000
Explanation:
Data provided in the question:
Total amount invested = $24,000
Total yearly interest = $1,260
Now,
Let the amount invested at 4% annual simple interest be 'x'
Thus,
the amount invested at 7% annual simple interest will be $24,000 - x
Total interest earned = Interest at 4% + Interest at 7%
$1,260 = 0.04x + 0.07(24,000 - x)
or
$1,260 = 0.04x + 1680 - 0.07x
or
-420 = -0.03x
or
x = $14,000
Hence,
Amount invested at 4% is $14,000
Amount invested at 7% is (24,000 - 14,000) = $10,000