Answer:if six sells a total of 70,000, his total earnings at the end of the month would be 13,600.Breakdown of Earnings:Basic Salary: 12,000Sales Amount: 70,000Commission on Sales Above 50,000:Sales over threshold: 70,000 - 50,000 = 20,000Commission: 20,000 × 0.08 = 1,600Total Earnings: 12,000 + 1,600 = 13,600