ANSWER
Therefore, the amount contributed by Damarius is $ 108,000 and the Interest earned is $103,966.64
EXPLANATION
Given;
Monthly deposit is;
[tex]300[/tex]Since, Damarius invested $ 300 each month for 30 years.
The Total principal investment for 30 years would be;
[tex]\begin{gathered} 300\times30\times12 \\ =108000 \end{gathered}[/tex]Hence, Damarius account balance after 30 years is the principal investment plus the interest.
Hence, Given that he has an account balance of $211,966.64.
Damarius interest equals;
[tex]\begin{gathered} 211966.64-108000 \\ =103966.64 \end{gathered}[/tex]Therefore, the amount contributed by Damarius = $ 108,000 and the Interest earned = $ 103,966.64