The salary plus commission employee earned $3,500 in January. Let his amount of sales for the month of January be x, then $2,000 + 3% of x = $3,500. 0.03x = $3,500 - $2,000 = $1,500 x = $1,500 / 0.03 = $50,000 The straight commission employee earned $3,850 in January. Let his amount of sales for the month of January be y, then 7% of y = $3,850. 0.07y = $3,850 y = $3,850 / 0.07 = $55,000 The graduated commission employee earned $3,600 in January. Let his amount of sales for the month of January be z, then 5% of $40,000 + 8% of z = $3,600. 0.05 x 40,000 + 0.08z = $3,600 $2,000 + 0.08z = $3,600 0.08z = $3,600 - $2,000 = $1,600 z = $1,600 / 0.08 = $20,000 Total sales for the graduated commission employee = $40,000 + $20,000 = $60,000 Therefore, the graduated commission employee had the largest dollar amount in sales of $60,000 for the month of January