The annual interest on an $18,000 investment exceeds the interest earned on a $12,000 investment by $288. The $18,000 is invested at a 0.6% higher rate of interest than the $12,000. What is the interest rate of each investment?

Question

The annual interest on an $18,000 investment exceeds the interest earned on a $12,000 investment by $288.  The $18,000 is invested at a 0.6% higher rate of interest than the $12,000.  What is the interest rate of each investment?

anonymous · Answer

If someone could just help me get the formula I will try to solve it myself :)

kropot72 · Answer

Let the interest rate on the $12,000 be i.
Then the interest rate on the $18,000 will be i + 0.006 ( expressed as a decimal).
Now we can write the following equation:
18000(i + 0.006) - 12000i = 288

Now you need to solve the equation to find the value of i, and then convert that value to a percentage rate of interest.