Joe invested $12,000, part at 6% interest and part at 8% interest. In the
first year he earned $860 in interest. How much was invested at each rate?
Answer _____________
To solve this problem, let's assume that Joe invested x dollars at 6% interest and (12000 - x) dollars at 8% interest.
To calculate the interest earned from the first investment, we use the formula: Interest = Principal * Rate.
For the first investment at 6% interest, the interest can be calculated as: (x * 0.06).
For the second investment at 8% interest, the interest can be calculated as: ((12000 - x) * 0.08).
According to the problem, the total interest earned from both investments is $860. So, we can write the equation: (x * 0.06) + ((12000 - x) * 0.08) = 860.
Let's solve this equation to find the value of x:
0.06x + 0.08(12000 - x) = 860
0.06x + 960 - 0.08x = 860
0.06x - 0.08x = 860 - 960
-0.02x = -100
x = (-100) / (-0.02)
x = 5000
Therefore, Joe invested $5,000 at 6% interest and $7,000 (12000 - 5000) at 8% interest.
.06x + .08(12000 - x) = 860
Solve for x and then 12000 - x.