Final answer:
Demitri earned a commission of 8% on the artwork he sold.
Step-by-step explanation:
To find the percentage commission Demitri earned, we need to divide the commission earned by the total amount of artwork sold and then multiply by 100.
Commission earned = $10
Total artwork sold = $125
Percentage commission earned = (Commission earned / Total artwork sold) * 100
Percentage commission earned = ($10 / $125) * 100 = 8%
Therefore, Demitri earned a commission of 8% on the artwork he sold.