Let, money in loan with 12% interest is x.
So, money in loan with 10% interest is 15000-x.
Now , sum of interest :
[tex]\dfrac{12x}{100}+\dfrac{10(15000-x)}{100}=1600\\\\12x+150000-10x=160000\\\\2x=10000\\\\x=5000[/tex]
Therefore, money on 12% interest is $5000 and 10% interest is $10000.
Hence, this is the required solution.