From the given information, we know that the sum of the interest must be equal to the total annual interest of $15,000. So, we can write

where x denotes the amount of money at 10% and (175000 -x) the amount of money at 8%. Then, our last equation is equivalent to

Then, by subtracting 14000 to both sides, we have

and by collecting the terms on the left hand sides, we have

Now, by dividing both sides by 0.02, we obtain

Then, $95,000 is the amount paid off at 10%.
Now, by substituting this result into (175000 -x), which corresponds to the amount paid off at 8%, we get

Therefore, the answer is: $95,000 amount paid off at 10% and $80,000 amount paid off at 8%