Blackwell Co. has credit sales of $317,428, costs of goods sold of $151,217, and average accounts receivable of $28,744.

Hello, I'm preparing for my final and I need help with this problem:

Blackwell Co. has credit sales of $317,428, costs of goods sold of $151,217, and average accounts receivable of $28,744. How long on average does it take the firm's credit customers to pay for their purchases?