The ratio that provides an estimate of the number of days, on average, that it takes for customers to pay their accounts is the:

days' sales in receivables

current ratio.

accounts receivable turnover.

acid-test ratio.

Marie's Clothing Store had an accounts receivable balance of $420,000 at the beginning of the year and a year-end balance of $510,000. Net credit sales for the year totaled $2,100,000. The average collection period of the receivables was:

41 days.

52 days.

81 days.

91 days.