i dont understand this question

A man has $300,000 invested in three investments. The first earns 13%, the second earns 11%, and the third earns 8%. His annual interest income from the investments is $28,870.00 and the amount invested at 8% is three times the amount at 13%. The amount invested at 13% is and the interest is The amount invested at 11% is and the interest is The amount invested at 8% is and the interest is