The total loan was $18,000.
Let's set x as the amount that was loaned at 8% (0.08 in decimal form)
Thus, the amount that was loaned at 16% (0.16 in decimal form) is (18,000-x).
If in one year the total interest received was $2500, we can state the next equation:
Apply the distributive property and solve for x:
So, of the $18,000 the bank loaned $4750 at 8%.