Kim is a medical supplies salesperson. Each month she receives a 5% commission on all her sales of medical supplies up to $20,000 and 8.5% on her total sales over $20,000. Her total commission for May was $3,975. What were her sales for the month of May?

Answer: her sales for the month of May is $55000

Step-by-step explanation:

Let x represent her total sales for the month of May.

Each month she receives a 5% commission on all her sales of medical supplies up to $20,000. This means that for her first sales worth $20000, she earns a commission of

5/100 * 20000 = 1000

She also earns 8.5% on her total sales over $20,000. This means that for sales over $20000, she earns

8.5/100 (x - 20000) = 0.085x - 1700

Her total commission for May was $3,975. The expression becomes

1000 + 0.085x - 1700 = 3975

0.085x = 3975 + 1700 - 1000

0.085x = 4675

x = 4675/0.085

x = 55000