Final answer:
Hassan has earned approximately $38,066.48 over the past 10 years playing the accordion.
Step-by-step explanation:
To find out how much Hassan has earned over the past 10 years playing the accordion, we can use the concept of compound interest. Since his income has increased by 15% each year, we can consider his income as an investment with an annual interest rate of 15%. We start with his income in the first year, $12,000, and calculate the total income over 10 years by multiplying it by (1 + 0.15) to the power of 10:
Total income = $12,000 × (1 + 0.15)^10 = $12,000 × 1.15^10 = $12,000 × 3.17220638 = $38,066.48
Therefore, Hassan has earned approximately $38,066.48 over the past 10 years playing the accordion.